Petravchuk , A.P. (1988) “Lie algebras, expanded into the sum of Abelian and nilpotent subalgebras”, Ukrains’kyi Matematychnyi Zhurnal, 40(3), pp. 385–388. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/9153 (Accessed: 7 December 2025).