Intuitionistic Fuzzy Subgroupoids. - Kul Hur; Su Youn Jang; Hee Won Kang (Int. J. Fuzzy Log. Intell. Syst., 2003)

Intuitionistic H-fuzzy relations. - Kul Hur; Su Youn Jang; Hee Won Kang (Int. J. Math. Math. Sci., 2005)

Union of Intuitionistic Fuzzy Subgroups. - Kul Hur; Hee Won Kang; Jang-Hyun Ryou (Int. J. Fuzzy Log. Intell. Syst., 2006)