G. Christou, P. Zaphiris, C. Ang, and E. Law. CHI '11 Extended Abstracts on Human Factors in Computing Systems, page 879--882. New York, NY, USA, ACM, (2011)
E. Law, V. Roto, M. Hassenzahl, A. Vermeeren, and J. Kort. Proceedings of the 27th international conference on Human factors in computing systems, page 719--728. New York, NY, USA, ACM, (2009)