C. Shaffer, V. Karavirta, A. Korhonen, and T. Naps. Proceedings of the Eleventh Koli Calling International Conference on Computing Education Research, page 112--117. Koli National Park, Finland, (November 2011)
L. Aalto, N. Göthlin, J. Korhonen, and T. Ojala. Proceedings of the 2nd international conference on Mobile systems, applications, and services, page 49--58. New York, NY, USA, ACM, (2004)