S. Parusheva, Y. Aleksandrova, P. Petrov. A STUDY OF THE USE OF SOCIAL MEDIA IN HIGHER EDUCATION INSTITUTIONS IN BULGARIA. 4th International Multidisciplinary Scientific Conference on Social Sciences and Arts SGEM 2017, 2017, pp. 19-26. https://doi.org/10.5593/sgemsocial2017/14/S04.003