@article{DAN_1977_232_4_a11,
     author = {L. G. Mustafaev and R. B. Feizullaev},
     title = {Semiheaps of multivalued mappings of topological spaces},
     journal = {Doklady Akademii Nauk},
     pages = {777--779},
     year = {1977},
     volume = {232},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1977_232_4_a11/}
}