For citations:

Chikake T.M., Bazanova E.M., Gorizontova A.V. Multi-tier linguistic feature engineering for CEFR classification: a comprehensive analysis of deterministic and machine learning-based features. Modeling and Analysis of Information Systems. 2026;33(1):6-29. (In Russ.) https://doi.org/10.18255/1818-1015-2026-1-6-29