D. Palacio, G. Cabanac, C. Sallaberry, and G. Hubert. Research and Advanced Technology for Digital Libraries, volume 6273 of Lecture Notes in Computer Science, Springer Berlin / Heidelberg, 10.1007/978-3-642-15464-5\_34.(2010)
K. Church, and N. Oliver. Proceedings of the 13th International Conference on Human Computer Interaction with Mobile Devices and Services, page 67--76. New York, NY, USA, ACM, (2011)
J. Feng, M. Johnston, and S. Bangalore. Proceedings of the 20th international conference companion on World wide web, page 293--294. New York, NY, USA, ACM, (2011)