1. Blackboard., Blackboard. http://uki.blackboard.com/sites/international/globalmaster/.
2. Blinov D. (2012). Statistics of the usage of the mobile devices, platforms and applications. Retrieved from: http://beamteam.ru/2012/09/mobile-platforms-share-2012/.
3. J'son & Partners Consulting (2013). The marker of mobile applications in Russian and worldwide. Retrieved from: http://www.json.ru/poleznye_materialy/free_market_watches/analytics/rynok_mobilnyh_prilozhenij_v_rossii_i_mire/.
4. Kuali Foundation. http://www.kuali.org/.
5. Kudzev, A. (2006). E-learning system based on the enriching learning system. Papers and articles, Novisibirsk State Technical University, volume 4(46), pages 55-60.