Ushvitskiy, Lev, Tat’yana Kulagovskaya, Anna Ter-Grigor’yants, Natalia Maslennikova, and Ekaterina Puchkova. 2019. “Competency-Based Approach to the Assessment of Specialists Using the Theory of Fuzzy Sets”. Amazonia Investiga 8 (22), 31-39. https://amazoniainvestiga.info/index.php/amazonia/article/view/25.