@article{700897,
     title = {Preclosed multivalued mappings},
     booktitle = {General Topology and its Relations to Modern Analysis and Algebra},
     series = {GDML\_Books},
     publisher = {Academia Publishing House of the Czechoslovak Academy of Sciences},
     address = {Praha},
     year = {1967},
     pages = {108-110},
     zbl = {0162.26801},
     url = {http://dml.mathdoc.fr/item/700897}
}

Dinh-Nho-Chuöng. Preclosed multivalued mappings, dans General Topology and its Relations to Modern Analysis and Algebra, GDML_Books,  (1967), pp. 108-110. http://gdmltest.u-ga.fr/item/700897/