Golikov, A. “Investigation of Lettersa As Knowledge Aggregates: Opportunities and Limitations”. Visnyk of V. N. Karazin Kharkiv National University. Series Sociological Studies of Contemporary Society: Methodology, Theory, Methods, Vol. 39, Feb. 2018, pp. 90-94, https://periodicals.karazin.ua/ssms/article/view/9895.