[1] S. A. Ahanger and A. H. Shah, On zigzag theorem for commutative pomonoids and certain closed and absolutely closed monoids and pomonoids, Contrbutions to Algebrra and Geometry, (1) 71 (2019), 9–21.
[2] S. A. Ahanger and A. H. Shah, Epis, dominions and varieties of commutative posemigroups, Asian-European Journal of Mathematics, (4) 14 (2021), 14 pages.
[3] S. A. Ahanger,A . H. Shah and N. M. Khan, Permutative varieties of posemigroups, Commuications in Algebra, (7) 49 (2021), 2758-2774.
[4] A. H. Clifford and G. B. Preston, The Algebraic Theory of Semigroups, Math. Surveys, Vol. I, II, (1961, 1967).
[5] P. M. Higgins, Epis are onto for generalised inverse semigroups, Semigroup Forum, 23 (1981), 255-259.
[6] J. M. Howie and J. R. Isbell, Epimorphisms and dominions II, J. Algebra, 6 (1967), 7-21.
[7] J. M. Howie, Fundamentals of Semigroup Theory, Clarendon Press, Oxford, 1995.
[8] H. E. Scheiblich, On epics and domonions of bands, Semigroup Forum, 13 (1976), 103-114.
[9] N. Sohail and L. Tart, Dominions, zigzags and epimorphism for partially ordered semigroups, Acta Commen. Univ. Tartu. Math., (1) 18 (2014), 81-91.