1. M. E. Abd El-Monsef, S. N. El-Deeb and R.A. Mahmound, β-open sets and β-continuous mapping,Bull. Fac. Sci. Assiut Univ.,12 (1983), 77–90.
2. N. Ajmal and J. K. Kohli, Properties of hyperconnected spaces, their mappings into Hausdorff spaces and embeddings into hyperconnected spaces,Acta Math. Hungar.,60 (1992), 41–49.
3. D. Andrijevic, Semi-preopen sets,Mat. Vesnik,38 (1986), 24–32.
4. S. P. Arya and Mamata Deb, On mappings almost continuous in the sense of Frolík,Math. Student,41 (1973), 311–321.
5. S. G. Crossley and S. K. Hildebrand, Semi-closure,Texas J. Sci.,22 (1971), 99–112.