Breckner, Wolfgang W., and Gheorghe Orbán. “On the Continuity of Convex Mappings”. Anal. Numér. Théor. Approx. 6, no. 2 (August 1, 1977): 117–123. Accessed April 11, 2025. https://ictp.acad.ro/jnaat/journal/article/view/1977-vol6-no2-art2.