Khomenko О. M., “α-Primitive Elements in the Generalized Verma Modules”, Ukr. Mat. Zhurn., vol. 52, no. 8, pp. 1135–1140, Aug. 2000, Accessed: Feb. 17, 2026. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/4518