Order relations on symmetric semigroups of transformations and on their homomorphic images. M.G. Mogilevskii (1980) Semigroup forum
Order theoretic variants of the fundamental theorem of compact semigroups. S.D. Hippisley-Cox (1994) Semigroup forum
Ordered sets which support inverse semigroups : Three examples. B.M. Schein, L. Li (1984) Semigroup forum
Ordering the local subsemigroups of a semigroup. K.D. jr. Magill, P.R. Misra (1986/1987) Semigroup forum
Orthodox bands of modules Francis Pastijn (1975/1976) Groupe d'étude d'algèbre Groupe d'étude d'algèbre
Orthodox Γ -semigroups. Sen, M.K., Saha, N.K. (1990) International Journal of Mathematics and Mathematical Sciences