HIRIART-URRUTY, J. -b. Lipschitz $r$-continuity of the approximative subdifferential of a convex function. MATHEMATICA SCANDINAVICA, [S. l.], v. 47, p. 123–134, 1980. DOI: 10.7146/math.scand.a-11878. Disponível em: https://tidsskrift.dk/math/article/view/11878. Acesso em: 14 aug. 2026.