Two theorems on existence of solutions of a quasilinear singular differential-operator equation. Neliniini Kolyvannya, [S. l.], v. 3, n. 3, p. 358–364, 2000. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/126. Acesso em: 22 jan. 2026.