BUDNYTS'KA, N. V.; RYBALKINA, T. V. Realization of a closed 1-form on closed oriented surfaces. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 64, n. 6, p. 739–751, 2012. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2613. Acesso em: 5 dec. 2025.