1. American Mathematical Society (2010), 2010 Mathematics Subject Classification, available at: www.ams.org/msc/msc2010.html (accessed 4 March 2017).
2. Association for Computing Machinery (ACM) (2012), Computing Classification System – 2012 Revision, available at: http://dl.acm.org/ft_gateway.cfm?id=2371137&ftid=1290921&dwn=1 (accessed 4 March 2017).
3. Towards tool support for agile modeling: sketching equals modeling,2012
4. California State University (1997), MERLOT Project, available at: www.merlot.org (accessed 3 March 2017).