Попов, Сергей Леонидович. 1. “The Regularities of Perceptually-Logical Evolution of Russian Morphology: Nouns, Adjectives, Numerals”. The Journal of V. N. Karazin Kharkiv National University. Series “Philology”, no. 74 (1), 138-44. https://periodicals.karazin.ua/philology/article/view/6752.