Gašević, Dragan, Jelena Jovanović, Colin Knight, and Griff Richards. “Ontologies for Effective Use of Context in E-Learning Settings”. The International Review of Research in Open and Distributed Learning 9, no. 1 (February 26, 2008). Accessed April 19, 2019. http://www.irrodl.org/index.php/irrodl/article/view/531.