HIRIART-URRUTY, J. -b. Lipschitz $r$-continuity of the approximative subdifferential of a convex function. Mathematica Scandinavica, Berkeley, CA, United States, v. 47, p. 123–134, 1980. DOI: 10.7146/math.scand.a-11878. Disponível em: https://journals.msp.org/mscand/article/view/1767. Acesso em: 25 jul. 2026.