BEDRATYUK, L. P. Kernels of derivations of polynomial rings and Casimir elements. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 62, n. 4, p. 435–452, 2010. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2878. Acesso em: 5 dec. 2025.