BASALAEV, S. G.; VODOPYANOV, S. K. Approximate differentiability of mappings of Carnot–Carathéodory spaces. Eurasian Mathematical Journal, [S. l.], v. 4, n. 2, p. 10–48, 2013. Disponível em: https://emj.enu.kz/index.php/main/article/view/530. Acesso em: 9 oct. 2025.