BOGDANSKII, Yu. V.; STATKEVYCH, V. M. Nonlinear equations with essentially infinite-dimensional differential operators. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 62, n. 11, p. 1571–1576, 2010. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2981. Acesso em: 5 dec. 2025.