1. Integrals of set-valued functions;Aumann;J. Math. Anal. Appl.,1965
2. Topological Spaces;Berge,1963
3. General Topology, Parts 1 and 2;Bourbaki,1966
4. Integration;Bourbaki,1965
5. T. F. Bridgland. Trajectory integrals of set valued functions, (to appear).