Skip to main content
Log in

ScholarRec: a scholars’ recommender system that combines scholastic influence and social collaborations in academic social networks

  • Regular Paper
  • Published:
International Journal of Data Science and Analytics Aims and scope Submit manuscript

Abstract

Identifying and recommending influential scholars is one of the leading applications of scholarly data analytic. The existing methods to identify influential scholars focus on scholastic influence or social collaborations. In the former approach, scholar’s scientific productivity is anatomized, whereas in the latter one, scholar’s collaborations are analyzed. To accurately measure a comprehensive influence of a scholar, it is essential to combine scholastic influence and social collaborations. The purpose of this research is to develop a recommender system, ScholarRec, which combines scholastic influence and social collaborations; hence, accurately and comprehensively identifies influential scholars from Academic Social Networks (ASNs). To measure scholastic influence, apart from scientific productivity, ScholarRec incorporates scholar’s active engagement in information propagation and knowledge dissemination. To measure the degree of social collaborations, ScholarRec explores follower and following connections among scholars instead of traditional co-author and co-citation relations. The performance of ScholarRec is evaluated on two well-known ASNs, ResearchGate (RG) and Academia. User demographic features demonstrating scholar’s scholastic and social contributions are collected for a set of scholars. To identify the significance of each feature included in ScholarRec, a weighting scheme is developed. It assigns an appropriate weight to each feature based on its significance in influence calculation. The weighted features help in generating unique ranks to influential scholars. The developed weight assignment technique also makes ScholarRec applicable to different ASNs with diverse features. The results reveal that ScholarRec accurately identifies and uniquely recommends influential scholars for RG and Academia.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Subscribe and save

Springer+ Basic
$34.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or eBook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10

Similar content being viewed by others

Explore related subjects

Discover the latest articles, news and stories from top researchers in related subjects.

Notes

  1. https://ideas.repec.org/top/.

  2. https://www.ssrn.com/index.cfm/en/top-authors/.

  3. https://www.infodocket.com/2021/11/16/clarivate-releases-annual-highly-cited-researchers-list/.

  4. http://www.neo4j.org.

References

  1. Agarwal, A., Durairajanayagam, D., Tatagari, S., Esteves, S.C., Harlev, A., Henkel, R., Roychoudhury, S., Homa, S., Puchalt, N.G., Ramasamy, R., et al.: Bibliometrics: tracking research impact by selecting the appropriate metrics. Asian J. Androl. 18(2), 296 (2016)

    Article  Google Scholar 

  2. Al-Asadi, M., Tasdemir, S.: A tutorial for creating a recommendation system for articles by using python tools (2020)

  3. Alonso, S., Cabrerizo, F.J., Herrera-Viedma, E., Herrera, F.: hg-index: A new index to characterize the scientific output of researchers based on the h-and g-indices. Scientometrics 82(2), 391–400 (2010)

    Article  Google Scholar 

  4. Alshareef, A.M., Alhamid, M.F., El Saddik, A.: Recommending scientific collaboration based on topical, authors and venues similarities. In: 2018 IEEE International Conference on Information Reuse and Integration (IRI), pp 55–61, (2018) https://doi.org/10.1109/IRI.2018.00016

  5. Amjad, T., Daud, A.: Indexing of authors according to their domain of expertise. Malaysian J. Library Inf. Sci. 22, 69–82 (2017)

    Article  Google Scholar 

  6. Amjad, T., Daud, A., Akram, A., Muhammed, F.: Impact of mutual influence while ranking authors in a co-authorship network. Kuwait J. Sci. 43(3), 101–109 (2016)

    Google Scholar 

  7. Amjad, T., Daud, A., Che, D., Akram, A.: Muice: Mutual influence and citation exclusivity author rank. Inf. Process. Manag. 52(3), 374–386 (2016). https://doi.org/10.1016/j.ipm.2015.12.001

    Article  Google Scholar 

  8. Amjad, T., Daud, A., Aljohani, N.: Ranking authors in academic social networks: a survey. Library Hi Tech 36(1), 97–128 (2018). https://doi.org/10.1108/LHT-05-2017-0090

    Article  Google Scholar 

  9. Anbalagan, M., Thangavel, R., Balasubramani, J.: Research contributions of indian universities in researchgate: An analysis. J. Adv. Library Inf. Sci. 7(1), 1–6 (2018)

    Google Scholar 

  10. Badami, M., Tafazzoli, F., Nasraoui, O.: A case study for intelligent event recommendation. Int. J. Data Sci. Anal. (2018). https://doi.org/10.1007/s41060-018-0120-3

    Article  Google Scholar 

  11. Bai, X., Zhang, F., Hou, J., Lee, I., Kong, X., Tolba, A., Xia, F.: Quantifying the impact of scholarly papers based on higher-order weighted citations. PLoS ONE 13(3), e0193192 (2018). https://doi.org/10.1371/journal.pone.0193192. (http://europepmc.org/articles/PMC5875758)

    Article  Google Scholar 

  12. Balasubramani, J., Thangavel, R.: Research contributions and utilization of researchgate by central universities in india: An analytical study. Library Philosophy and Practice, (2019)

  13. Bibi, F., Khan, H., Iqbal, T., Farooq, M., Mehmood, I., Nam, Y.: Ranking authors in an academic network using social network measures. Appl. Sci. 8, 1824 (2018). https://doi.org/10.3390/app8101824

    Article  Google Scholar 

  14. Bornmann, L.: Do altmetrics point to the broader impact of research? an overview of benefits and disadvantages of altmetrics. J. Informet. 8(4), 895–903 (2014)

    Article  Google Scholar 

  15. Bornmann, L.: Measuring impact in research evaluations: a thorough discussion of methods for, effects of and problems with impact measurements. High. Educ. 73(5), 775–787 (2017)

    Article  Google Scholar 

  16. Bornmann, L., Haunschild, R.: Do altmetrics correlate with the quality of papers? a large-scale empirical study based on f1000prime data. PLoS ONE 13(5), e0197133 (2018)

    Article  Google Scholar 

  17. Bornmann, L., Haunschild, R., Adams, J.: Do altmetrics assess societal impact in a comparable way to case studies? an empirical test of the convergent validity of altmetrics based on data from the uk research excellence framework (ref). J. Informet. 13(1), 325–340 (2019)

    Article  Google Scholar 

  18. Boudry, C., Durand Barthez, M.: Use of author identifier services (orcid, researcherid) and academic social networks (academia.edu, researchgate) by the researchers of the university of caen normandy (france): A case study. PloS One 15, 0238583 (2020). https://doi.org/10.1371/journal.pone.0238583

    Article  Google Scholar 

  19. Brown, R.J.: A simple method for excluding self-citation from the h-index: the b-index. Online Information Review, (2009)

  20. Bulut, B., Kaya, B., Alhajj, R., Kaya, M.: A paper recommendation system based on user’s research interests. In: 2018 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM), IEEE, pp. 911–915 (2018)

  21. Bulut, B., Gündoğan, E., Kaya, B., Alhajj, R., Kaya, M.: User’s research interests based paper recommendation system: A deep learning approach. In: Putting Social Media and Networking Data in Practice for Education, Planning, Prediction and Recommendation, Springer, pp. 117–130 (2020)

  22. Burrell, Q.: Hirsch’s h-index: A stochastic model. J. Informet. 1, 16–25 (2007). https://doi.org/10.1016/j.joi.2006.07.001

    Article  Google Scholar 

  23. Chunlei, Z., Chengrui, C., Tan, Z., Yanyun, C.: Study on tdh-index of library & information science scholars in china. Library Inf. Serv. 61(19), 96 (2017)

    Google Scholar 

  24. Claro, J., Costa, C.A.: A made-to-measure indicator for cross-disciplinary bibliometric ranking of researchers performance. Scientometrics 86(1), 113–123 (2011)

    Article  Google Scholar 

  25. Desai, M., Mehta, R.G., Rana, D.P.: An empirical analysis to identify the effect of indexing on influence detection using graph databases. Int. J. Innov. Technol. Explor. Eng. 8(9S), 414–421 (2019)

    Article  Google Scholar 

  26. Desai, M., Mehta, R., Rana, D.: RGNet: The Novel Framework to Model Linked ResearchGate Information into Network Using Hierarchical Data Rendering. Springer, chap 4, pp. 37–45 (2021). https://doi.org/10.1007/978-981-15-5243-4_4

  27. Ding, Y.: Scientific collaboration and endorsement: Network analysis of coauthorship and citation networks. J. Informet. 5(1), 187–203 (2011). https://doi.org/10.1016/j.joi.2010.10.008

    Article  Google Scholar 

  28. Ding, Y., Cronin, B.: Popular and/or prestigious? measures of scholarly esteem. Inf. Process. Manag. 47, 80–96 (2010). https://doi.org/10.1016/j.ipm.2010.01.002

    Article  Google Scholar 

  29. EGGHE, L.: An improvement of the h-index: The g-index. ISSI Newsletter 2, (2006)

  30. El Alaoui, D., Riffi, J., Aghoutane, B., Sabri, A., Yahyaouy, A., Tairi, H.: Overview of the main recommendation approaches for the scientific articles. In: International Conference on Business Intelligence, Springer, pp. 107–118, (2021)

  31. Espinoza Vasquez, F.K., Caicedo Bastidas, C.E.: Academic social networking sites: A comparative analysis of their services and tools. In: iConference 2015 Proceedings, (2015)

  32. Fang, Z., Chongxin, T.: Research on academic influence of scholars in the discipline of library and information science (2008–2017). Library Work and Study p. 05, (2018)

  33. Färber, M., Thiemann, A., Jatowt, A.: Citewerts: A system combining cite-worthiness with citation recommendation. In: European Conference on Information Retrieval, Springer, pp. 815–819, (2018)

  34. Fiala, D., Rousselot, F., Jezek, K.: Pagerank for bibliographic networks. Scientometrics 76, 135–158 (2008). https://doi.org/10.1007/s11192-007-1908-4

    Article  Google Scholar 

  35. Gao, B.J., Kumar, G.K.J.: Corank: Simultaneously ranking publication venues and researchers. In: 2019 IEEE International Conference on Big Data (Big Data), pp. 6055–6057, (2019) https://doi.org/10.1109/BigData47090.2019.9006349

  36. Gasparyan, A.Y., Nurmashev, B., Yessirkepov, M., Endovitskiy, D.A., Voronov, A.A., Kitas, G.D.: Researcher and author profiles: opportunities, advantages, and limitations. J. Korean Med. Sci. 32(11), 1749–1756 (2017)

    Article  Google Scholar 

  37. Ghosal, T., Chakraborty, A., Sonam, R., Ekbal, A., Saha, S., Bhattacharyya, P.: Incorporating full text and bibliographic features to improve scholarly journal recommendation. 2019 ACM/IEEE Joint Conference on Digital Libraries (JCDL) pp. 374–375, (2019)

  38. Gollapalli, S.D., Mitra, P., Giles, C.L.: Ranking experts using author-document-topic graphs. In: Proceedings of the 13th ACM/IEEE-CS Joint Conference on Digital Libraries, Association for Computing Machinery, New York, NY, USA, JCDL ’13, p 87–96, (2013) https://doi.org/10.1145/2467696.2467707, https://doi.org/10.1145/2467696.2467707

  39. Guilarte, O., Barbosa, S., Pesco, S.: A Collaborative Support for Recommending References in Papers. pp 42–48, (2019) https://doi.org/10.5753/sibgrapi.est.2019.8300

  40. Hammook, Z., Mišić J, Misic V (2015) Crawling researchgate.net to measure student/supervisor collaboration. In: Proceedings of the 2015 IEEE Global Communications Conference (GLOBECOM), pp. 1–6, https://doi.org/10.1109/GLOCOM.2014.7417042

  41. Hasnain, M., Pasha, M.F., Ghani, I., Imran, M., Alzahrani, M.Y., Budiarto, R.: Evaluating trust prediction and confusion matrix measures for web services ranking. IEEE Access 8, 90847–90861 (2020)

    Article  Google Scholar 

  42. Hirsch, J.E.: An index to quantify an individual’s scientific research output. Proc. Natl. Acad. Sci. 102(46), 16569–16572 (2005). https://doi.org/10.1073/pnas.0507655102. (https://www.pnas.org/content/102/46/16569)

    Article  MATH  Google Scholar 

  43. Hong, D., Baccelli, F.: On a Joint Research Publications and Authors Ranking (2012)

  44. Hou, J., Yang, X., Chen, C.: Measuring researchers’ potential scholarly impact with structural variations: Four types of researchers in information science (1979–2018). PLoS ONE 15(6), e0234347 (2020)

    Article  Google Scholar 

  45. Huang, L., Chen, X., Zhang, Y., Zhu, Y., Li, S., Ni, X.: Dynamic network analytics for recommending scientific collaborators. Scientometrics 126, 1–26 (2021). https://doi.org/10.1007/s11192-021-04164-x

    Article  Google Scholar 

  46. Iyengar, K., Balijepally, V.: Ranking journals using the dominance hierarchy procedure: an illustration with is journals. Scientometrics 102(1), 5–23 (2015). https://doi.org/10.1007/s11192-014-1444-y

    Article  Google Scholar 

  47. Jain, S., Khangarot, H., Singh, S.: Journal recommendation system using content-based filtering. Adv. Intell. Syst. Comput. (2018)

  48. Jeong, C., Jang, S., Park, E., Choi, S.: A context-aware citation recommendation model with bert and graph convolutional networks. Scientometrics 124(3), 1907–1922 (2020)

    Article  Google Scholar 

  49. Jin, B., Liang, L., Rousseau, R., Egghe, L.: The r-and ar-indices: Complementing the h-index. Chinese Sci. Bull. (2007). https://doi.org/10.1007/s11434-007-0145-9

    Article  Google Scholar 

  50. Katsaros, D., Akritidis, L., Bozanis, P.: The f index: Quantifying the impact of coterminal citations on scientists’ ranking. J. Am. Soc. Inform. Sci. Technol. 60, 1051–1056 (2009). https://doi.org/10.1002/asi.21040

    Article  Google Scholar 

  51. Khvatova, T.Y., Dushina, S.A.: Scientific online communication: The strategic landscape of researchgate users. (2019) https://doi.org/10.13140/RG.2.2.18535.09122 [Accessed:February 15, 2019]

  52. Koltun, V., Hafner, D.: The h-index is no longer an effective correlate of scientific reputation. (2021), arXiv preprint arXiv:2102.03234

  53. Kosmulski, M.: Maxprod-a new index for assessment of the scientific output of an individual, and a comparison with the h-index. Cybermet. Int. J. Sci. Inform. Bibliomet. (11):5, (2007)

  54. Li, X., Hao, J.: Construction of an evaluation index system for determining the academic impact of military medical scholars. BMJ Military Health 164(3), 164–169 (2018)

    Google Scholar 

  55. Liang, Z., Mao, J., Lu, K., Ba, Z., Li, G.: Combining deep neural network and bibliometric indicator for emerging research topic prediction. Inf. Process. Manag. 58, 102611 (2021). https://doi.org/10.1016/j.ipm.2021.102611

    Article  Google Scholar 

  56. Lima, H., Silva, T.H., Moro, M.M., Santos, R.L., Meira, W., Laender, A.H.: Aggregating productivity indices for ranking researchers across multiple areas. In: Proceedings of the 13th ACM/IEEE-CS Joint Conference on Digital Libraries, Association for Computing Machinery, New York, NY, USA, JCDL ’13, pp. 97–106, (2013) https://doi.org/10.1145/2467696.2467715

  57. Maia, L.F.M.P., Lenzi, M., Rabello, E.T., Oliveira, J.: Scientific collaboration in zika: identification of the leading research groups and researchers via social network analysis. Cadernos de saude publica 35, (2019)

  58. Makarov, I., Gerasimova, O., Sulimov, P., Zhukov, L.: Co-authorship Network Embedding and Recommending Collaborators via Network Embedding: 7th International Conference, AIST 2018, Moscow, Russia, July 5–7, 2018, Revised Selected Papers, pp. 32–38, (2018), https://doi.org/10.1007/978-3-030-11027-7_4

  59. Makkizadeh F, Dehghan A, Mostafavi Ea (2020) Investigating association between social influence, productivity, and performance in co-author network of researchers in medical ethics. Med. Ethics History Med. 13(1), http://ijme.tums.ac.ir/article-1-6177-en.html

  60. Mangan, K.: Social networks for academics proliferate, despite some doubts. Chronicle Higher Educ. 58(35), 1–7 (2012)

    Google Scholar 

  61. Maqsood, S., Islam, A., Afzal, M., Masood, N.: A comprehensive author ranking evaluation of network and bibliographic indices, (2020) https://doi.org/10.22452/mjlis.vol25no1.2

  62. Namazi, M.R., Fallahzadeh, M.K.: Viewpoint n-index: A novel and easily-calculable parameter for comparison of researchers working in different scientific fields. Indian J. Dermatol Venereol Leprol 76(3), (2010)

  63. Nishioka, C., Große-Bölting, G., Scherp, A.: Influence of time on user profiling and recommending researchers in social media. In: Proceedings of the 15th International Conference on Knowledge Technologies and Data-driven Business, pp. 1–8, (2015)

  64. de Oliveira Lima, J., Oliveira, E.: Combining clustering and regression models for recommending researchers. In: Anais do IX Symposium on Knowledge Discovery, Mining and Learning, SBC, pp. 137–144 (2021)

  65. Ortega, J.L.: Toward a homogenization of academic social sites: A longitudinal study of profiles in academia edu, google scholar citations and researchgate. Online Inform. Rev. 41(6), 812–825 (2017)

    Article  Google Scholar 

  66. Rapple, C.: Understanding and supporting researchers’ choices in sharing their publications: the launch of the fairshare network and shareable pdf. Insights 31, (2018)

  67. Ravenscroft, J., Liakata, M., Clare, A., Duma, D.: Measuring scientific impact beyond academia: An assessment of existing impact metrics and proposed improvements. PLoS ONE 12(3), e0173152 (2017)

    Article  Google Scholar 

  68. Raza, S., Ding, C.: Progress in context-aware recommender systems - an overview. Comput. Sci. Rev. 31, 84–97 (2019)

    Article  MathSciNet  Google Scholar 

  69. Raza, S., Ding, C.: News recommender system: a review of recent progress, challenges, and opportunities. Artif. Intell. Rev. pp. 1 – 52 (2022)

  70. Rodrigues, M.W., Brandão, W.C., Zárate, L.E.: Recommending scientific collaboration from researchgate. In: 2018 7th Brazilian Conference on Intelligent Systems (BRACIS), pp. 336–341, (2018), https://doi.org/10.1109/BRACIS.2018.00065

  71. Rousseau, R.: New developments related to the hirsch index, (2006)

  72. Rowlands, I., Nicholas, D., Russell, B., Canty, N., Watkinson, A.: Social media use in the research workflow. Learned Publ. 24(3), 183–195 (2011)

    Article  Google Scholar 

  73. Savov, P., Jatowt, A., Nielek, R.: Identifying breakthrough scientific papers. Inf. Process. Manag. 57(2), 102168 (2020). https://doi.org/10.1016/j.ipm.2019.102168. (https://www.sciencedirect.com/science/article/pii/S0306457319303851)

    Article  Google Scholar 

  74. Sazzed, S.: Association between the rankings of top bioinformatics and medical informatics journals and the scholarly reputations of chief editors. Publications 9, 42 (2021). https://doi.org/10.3390/publications9030042

    Article  Google Scholar 

  75. Sharma, D., Kumar, B., Chand, S.: Recommending researchers in machine learning based on author-topic model. (2021), arXiv preprint arXiv:2109.02022

  76. Thelwall, M., Kousha, K.: Researchgate versus google scholar: Which finds more early citations? Scientometrics 112(2), 1125–1131 (2017)

    Article  Google Scholar 

  77. Tol, R.: The h-index and its alternatives: An application to the 100 most prolific economists. Scientometrics 80(2), 317–324 (2009)

    Article  Google Scholar 

  78. Wang, D., Liang, Y., Xu, D., Feng, X., Guan, R.: A content-based recommender system for computer science publications. Knowl.-Based Syst. 157, 1–9 (2018)

    Article  Google Scholar 

  79. Wang, J., Zhu, L., Dai, T., Wang, Y.: Deep memory network with bi-lstm for personalized context-aware citation recommendation. Neurocomputing 410, 103–113 (2020)

    Article  Google Scholar 

  80. Wang, Y., Ding, Z., Wei, X.X., Long, J.: Scholars influence evaluation based on time series heterogeneous network. In: 2021 13th International Conference on Measuring Technology and Mechatronics Automation (ICMTMA), pp 868–871, (2021) https://doi.org/10.1109/ICMTMA52658.2021.00198

  81. Wildgaard, L., Schneider, J.W., Larsen, B.: A review of the characteristics of 108 author-level bibliometric indicators. Scientometrics 101(1), 125–158 (2014). https://doi.org/10.1007/s11192-014-1423-3. (http://dx.doi.org/10.1007/s11192-014-1423-3)

    Article  Google Scholar 

  82. Wu, D., Fan, S., Yuan, F.: Research on pathways of expert finding on academic social networking sites. Inf. Process. Manag. 58(2), 102475 (2021). https://doi.org/10.1016/j.ipm.2020.102475. (https://www.sciencedirect.com/science/article/pii/S030645732030964X)

    Article  Google Scholar 

  83. Wu M, Zhang Y, Lu J, Lin H, Grosser M (2020) Recommending scientific collaborators: Bibliometric networks for medical research entities. pp. 480–487, https://doi.org/10.1142/9789811223334_0058

  84. Xie, Q., Zhu, Y., Huang, J., Du, P., Nie, J.Y.: Graph neural collaborative topic model for citation recommendation. ACM Trans. Inform. Syst. 40(3), 1–30 (2021)

    Google Scholar 

  85. Xue, Z., Couch, A.: A recommendation system for scientific water data. Int. J. Data Sci. Anal. 12, 1–15 (2021). https://doi.org/10.1007/s41060-021-00255-3

    Article  Google Scholar 

  86. Yan, E., Ding, Y.: Discovering author impact: A pagerank perspective. Inf. Process. Manag. 47, 125–134 (2010). https://doi.org/10.1016/j.ipm.2010.05.002

    Article  Google Scholar 

  87. Yan, W., Zhang, Y., Hu, T., Kudva, S.: How does scholarly use of academic social networking sites differ by academic discipline? a case study using researchgate. Inf. Process. Manag. 58, 102430 (2021). https://doi.org/10.1016/j.ipm.2020.102430

    Article  Google Scholar 

  88. Zhang, C.T.: The e-index, complementing the h-index for excess citations. PLoS ONE 4(5), e5429 (2009)

    Article  Google Scholar 

  89. Zhang, S., Zhao, D., Cheng, R., Cheng, J., Wang, H.: Finding influential papers in citation networks. In: in Proceedings of the IEEE 1st International Conference on Data Science in Cyberspace (DSC), pp. 658–662, (2016), https://doi.org/10.1109/DSC.2016.55

  90. Zhu, Y., Lin, Q., Lu, H., Shi, K., Qiu, P., Niu, Z.: Recommending scientific paper via heterogeneous knowledge embedding based attentive recurrent neural networks. Knowl.-Based Syst. 215, 106744 (2021)

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Contributions

Conceptualization was done by MD, RGM and DPR. Methodology was done by MD. Formal analysis and investigation were carried out by MD. Writing–original draft preparation were done by MD. Writing–review and editing were done by MD, RGM and DPR.

Corresponding author

Correspondence to Mitali Desai.

Ethics declarations

Conflicts of interest

The authors declare that they have no conflict of interest.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Desai, M., Mehta, R.G. & Rana, D.P. ScholarRec: a scholars’ recommender system that combines scholastic influence and social collaborations in academic social networks. Int J Data Sci Anal 16, 203–216 (2023). https://doi.org/10.1007/s41060-022-00345-w

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s41060-022-00345-w

Keywords