PRUSIŃSKA, A.; TRET’YAKOV, A. $p$-Regularity Theory. Tangent Cone Description in the Singular Case. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 67, n. 8, p. 1097–1106, 2015. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2048. Acesso em: 5 dec. 2025.