1. ECAR National study of undergraduate students and information technology, 2011 Report (2012). https://library.educause.edu/resources/2011/10/ecar-national-study-of-undergraduate-students-and-information-technology-2011-report . Accessed 22 Feb 2018
2. Blended learning. https://www.cte.cornell.edu/teaching-ideas/teaching-with-technology/blended-learning.html . Accessed 20 Feb 2018
3. Poon, J.: Use of blended learning to enhance the student learning experience and engagement in property education. Prop. Manag. 30(2), 129–156 (2012)
4. Amaral, K., Shank, J.: Enhancing student learning and retention with blended learning class guides (2010). https://er.educause.edu/articles/2010/12/enhancing-student-learning-and-retention-with-blended-learning-class-guides . Accessed 18 Feb 2018
5. Common European Framework of Reference for Languages: learning, teaching and assessment. Provisional edition. Council of Europe (2017). https://www.coe.int/en/web/common-european-framework-reference-languages/? . Accessed 30 Dec 2017