Черноватий, Л. М., and Н. М. Ковальчук. “Thematic Classification of English Abbreviations for Language Teaching Organizations. Introduction”. The Journal of V.N. Karazin Kharkiv National University. Series: Foreign Philology. Methods of Foreign Language Teaching, no. 91, June 2020, doi:10.26565/2227-8877-2020-91-21.