P. Fröhlich, M. Baldauf, S. Suette, D. Schabus, and M. Fuchs. Proceedings of the 2012 ACM annual conference on Human Factors in Computing Systems (CHI), Extended Abstracts, page 1787-1792. Austin, TX, USA, (May 2012)
L. Denoue, J. Adcock, S. Carter, P. Chui, and F. Chen. Proceedings of the 10th ACM symposium on Document engineering - DocEng '10, page 235. Manchester, United Kingdom, ACM Press, (2010)