Breckner, Wolfgang W., and Gheorghe Orbán. “On the Continuity of Convex Mappings”. Anal. Numér. Théor. Approx., vol. 6, no. 2, Aug. 1977, pp. 117-23, https://ictp.acad.ro/jnaat/journal/article/view/1977-vol6-no2-art2.