For citations:

Lagutina N.S., Lagutina K.V., Brederman A.M., Kasatkina N.N. Text classification by CEFR levels using machine learning methods and BERT language model. Modeling and Analysis of Information Systems. 2023;30(3):202-213. (In Russ.) https://doi.org/10.18255/1818-1015-2023-3-202-213