1. A certain class of topological spaces;Aull;Prace Math.,1967
2. C.E. Aull, Some base axioms for topology involving enumerability, in: Proc. Conf., Kanpur, General Topology and its Relations to Modern Analysis and Algebra, 1968, pp. 55–61
3. On a theorem of Cellina for set valued functions;Beer;Rocky Mountain J. Math.,1988
4. Topologies on Closed and Closed Convex Sets;Beer,1993
5. Theorems of Namioka and R.E. Johnson type for upper semicontinuous and compact valued set-valued mappings;Christensen;Proc. Amer. Math. Soc.,1982