@article{AUCMP_1989__30_2_a18,
     author = {Nikodem, Kazimierz},
     title = {A characterization of midconvex set-valued functions},
     journal = {Acta Universitatis Carolinae. Mathematica et Physica},
     pages = {125--129},
     publisher = {mathdoc},
     volume = {30},
     number = {2},
     year = {1989},
     mrnumber = {1046457},
     zbl = {0712.39027},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AUCMP_1989__30_2_a18/}
}