1. Normality and Martin’s axiom;Alster, K.;Fund. Math.,1976
2. Everywhere-dense subsets of topological spaces;Amirdžanov, G. P.;Dokl. Akad. Nauk SSSR,1974
3. H. R. Bennett, Quasi-developable spaces, Dissertation, Arizona State Univ., Tempe, Arizona, 1968.
4. K. Devlin and H. Johnsbråten, The Souslin problem, Lecture Notes in Math., vol. 405, Springer-Verlag, New York, 1975.
5. E. K. Van Douwen, The Pixley-Roy topology on spaces of subsets (preprint).