J. Kietzmann, and H. Tsang. Proceedings of the 15th Western Canadian Conference on Computing Education, page 14:1--14:5. New York, NY, USA, ACM, (2010)
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)