1. Hyperspaces of Sets;Nadler,1978
2. Topological properties of the spaces of regular fuzzy sets;Ouyang;J. Math. Anal. Appl.,1988
3. An embedding theorem for spaces of convex sets;Radstrom,1952
4. Functional Analysis;Rudin,1973
5. Treating a fuzzy subset as a projectable random subset;Peizhuang,1982