SAVCHIN, V.M.; HUYEN, L.T. Nonpotentiality of a diffusion system and the construction of a semi-bounded functional. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 104, n. 4, p. 118–129, 2021. DOI: 10.31489/2021m4/118-129. Disponível em: https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/486. Acesso em: 3 jul. 2025.