Last-modified: 2011-08-21 (日) 11:20:58
- The complement of a β-open set is called a β-closed set.
- Basu, C. K.; Afsan, B. M. Uzzal; Ghosh, M. K., A class of functions and separation axioms with respect to an operation. (English summary), Hacet. J. Math. Stat. 38 (2009), no. 2, 103-118.