1. J. P. Aubin, H. Frankowska, Set-Valued Analysis, Birhäuser, Boston, 1990.
2. C. Berge, Topological Spaces Including a Treatment of Multi-Valued Functions, Vector Spaces and Convexity, Oliver & Boyd, Edinburgh-London, 1963.
3. A. Cambini, L. Martein, Generalized convexity and optimization: Theory and Applications, Springer-Verlag, Berlin, 2009.
4. F. Deutsch, I. Singer, On single-valuedness of convex set-valued maps, Set-Valued Anal., no. 1, 1993, 97-103.
5. A. Göpfert, H. Riahi, C. Tammer, C. Zălinescu, Variational Methods in Partially Ordered Spaces, Springer-Verlag, New York, 2003.