1. Additive set-functions in abstract spaces;Alexandroff;Mat. Sb. (N.S.),1940
2. Alexandroff spaces;Arenas;Acta Math. Univ. Comenianae,1999
3. Soft set theory;Maji;Computers Math. Appl.,2003
4. Soft set theory—first results;Molodtsov;Computers Math. Appl.,1999
5. Soft set theory;Zadeh;Inform. Control,1965