G. Reinmann, A. Florian, and M. Schiefner. Digitale Medien für Lehre und Forschung, volume 55 of Medien in der Wissenschaft, Waxmann, Münster u.a., (2010)
M. Rajanen, and N. Iivari. Proceedings of the 11th international Conference on Open Source Systems (OSS 2015), volume 451 of IFIP Advances in Information and Communication Technology, page 58-67. Springer, (2015)
M. Rajanen, and N. Iivari. Proceedings of the 33rd Annual ACM Conference on Human Factors in Computing Systems, page 3413--3422. New York, NY, USA, ACM, (2015)