X. He, L. Liao, H. Zhang, L. Nie, X. Hu, and T. Chua. Proceedings of the 26th International Conference on World Wide Web, page 173–182. Republic and Canton of Geneva, CHE, International World Wide Web Conferences Steering Committee, (2017)
M. Claypool, P. Le, M. Wased, and D. Brown. Proceedings of the 6th international conference on Intelligent user interfaces, page 33--40. New York, NY, USA, ACM, (2001)