ZORII, N. V. Extremal problems dual to the Gauss variational problem. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 58, n. 6, p. 747–764, 2006. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3493. Acesso em: 6 dec. 2025.