1. β-Open sets and β-continuous mappings;Abd El-Monsef;Bull. Fac. Sci. Assiut. Univ.,1983
2. Semi-preopen sets;Andrijević;Mat. Vesnik.,1986
3. On b-open sets;Andrijević;Mat. Bech.,1996
4. Multifunctions and M-product spaces (Romanian);Bânzaru;Bul. Stiin. Teh. Inst. Politeh. Timisoara Ser. Mat. Fiz. Mec. Teor. Apl.,1972
5. Bânzaru T. On the upper semicontinuity of the upper topological limite for multifunction nets. Semin Mat Fiz Inst Politeh Timisoara 1983;59–64