R. Aigner, A. Pointner, T. Preindl, P. Parzer, and M. Haller. Proceedings of the 2020 CHI Conference on Human Factors in Computing Systems, page 1--13. New York, NY, USA, Association for Computing Machinery, (2020)event-place: Honolulu, HI, USA.
I. Harwarth, M. Maline, and E. DeBra. National Institute on Postsecondary Education, Libraries, and Lifelong Learning, Washingnton, DC, (June 1997)00056.