PSHENICHNY , B. N. Necessary conditions of extremum, penalty functions and regularity. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 44, n. 6, p. 805–812, 1992. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8013. Acesso em: 6 dec. 2025.