Isomov, Ismoil, et al. “E-PORTFOLIO AS A MEANS OF UPGRADING PROFESSIONAL COMPETENCE OF PEDAGOGICAL STAFF FROM HIGHER EDUCATIONAL INSTITUTIONS”. SOCIETY. INTEGRATION. EDUCATION. Proceedings of the International Scientific Conference, vol. 3, May 2017, pp. 472-8, https://doi.org/10.17770/sie2017vol3.2421.