Fuzzy (r, s)-preopen sets. - Seung-On Lee; Eun-Pyo Lee (Int. J. Fuzzy Log. Intell. Syst., 2005)

Fuzzy strongly (r, s)-semiopen sets. - Seung-On Lee; Eun-Pyo Lee (Int. J. Fuzzy Log. Intell. Syst., 2006)

Fuzzy pairwise (r, s)-irresolute mappings. - Seung-On Lee; Eun-Pyo Lee (Int. J. Fuzzy Log. Intell. Syst., 2009)

Fuzzy β-(r, s)-Open Sets in Smooth Bitopological Spaces. - Seung-On Lee; Eun-Pyo Lee (Int. J. Fuzzy Log. Intell. Syst., 2010)