[1] S. Abbas and W. Ashraf, On Closed Homotypical Varieties of Semigroups, J. Algebra Relat. Topics., 9(2) (2021), 83–95.
[2] S. Abbas, W. Ashraf and A. H. Shah, On dominions and varieties of bands, Asian-Eur. J. Math., 14(8) (2021), Article ID: 2150140.
[3] S. A. Ahanger and A. H. Shah, Epimorphisms, dominions and varieties of bands, Semigroup Forum, 100 (2020), 641–650.
[4] N. Alam and N. M. Khan, Epimorphism, closed and supersaturated semigroups, Comm. Algebra, 42(7) (2014), 3137–3146.
[5] N. Alam and N. M. Khan, On closed and supersaturated semigroups, Malays. J. Math. Sci., 9(3) (2015), 409–416.
[6] N. Alam and N. M. Khan, Special semigroup amalgams of quasi unitary subsemigroups and of quasi normal bands, Asian-Eur. J. Math., 6(1) (2013), Article ID: 1350010.
[7] A. H. Clifford and G. B. Preston, The Algebraic Theory of Semigroups, In: Mathematical Surveys and Monographs, 7(1), American Mathematical Society, 1961.
[8] P. M. Higgins, Techniques of Semigroup Theory, Oxford University Press, Oxford, 1992.
[9] J. M. Howie, Fundamentals of Semigroup Theory, Clarendon Press, Oxford, 1995.
[10] J. R. Isbell, Epimorphisms and dominions, In: Proceedings of the conference on Categorical Algebra, La Jolla, (1965), 232-246. Lange and Springer, Berlin, 1966.
[11] N. M. Khan, On saturated permutative varieties and consequences of permutation identities, J. Aust. Math. Soc. (Ser. A), 38(2) (1985), 186–197.
[12] H. E. Scheiblich, On epics and dominions of bands, Semigroup Forum, 13 (1976), 103–114.