Fuzzy quasi-ideals of ordered semigroups. Shabir, Muhammad; Khan, Asghar — 2011 Bulletin of the Malaysian Mathematical Sciences Society. Second Series
Ordered semigroups characterized by their ( ∈ , ∈ ∨ q ) -fuzzy bi-ideals. Jun, Young Bae; Khan, Asghar; Shabir, Muhammad — 2009 Bulletin of the Malaysian Mathematical Sciences Society. Second Series
𝒩 -fuzzy ideals in ordered semigroups. Khan, Asghar; Jun, Young Bae; Shabir, Muhammad — 2009 International Journal of Mathematics and Mathematical Sciences