[1] J. Araujo, M. Kinyon and J. Konieczny, Conjugacy in inverse semigroups, J. Algebra, 533 (2019) 142-173
[2] J. Araujo, M. Kinyon, J. Konieczny and A. Malheiro, Four notions of conjugacy for abstract semigroups, Proc. Roy. Soc. Edinburgh Sect. A: Mathematics, 147 No. 6 (2017) 1169-1214.
[3] J. Araujo, J. Konieczny and A. Malheiro, Conjugation in semigroups, J. Algebra, 403 (2014) 93-134.
[4] J. Koneiczny, A new definition of conjugacy for semigroups, J. Algebra and Appl., 17 No. 02 (2018) 1850032.
[5] G. Kudryavtseva and V. Mazorchuk, On conjugation in some transformation and Brauer-type semigroups, Publ. Math. Debrecen, 70 (2007) 19-43.
[6] G. Kudryavtseva and V. Mazorchuk, On three approaches to conjugacy in semigroups, Semigr. Forum, 78 (2009) 14-20.
[7] J. M. Howie, Fundamentals of Semigroup Theory, Oxford University Press, New York, 1995.
[8] T. Jech, Set Theory, Third Edition, Springer-Verlag, New York, 2006.
[9] G. Lallement, Semigroups and Combinatorial Applications, John Wiley and Sons, New York, 1979.
[10] F. Otto, Conjugacy in monoids with a special Church-Rosser presentation is decidable, Semigr. Forum, 29 (1984) 223-240.
[11] A. H. Shah, M. R. Parray, ~r notion of conjugacy in partial transformation semigroups, Korean J. Math., 30 No. 1 (2022) 115-125.
[12] L. Zhang, Conjugacy in special monoids, J. Algebra, 143 (1991) 487-497.
[13] L. Zhang, On the conjugacy problem for one-relator monoids with elements of finite order, Internat. J. Algebra Comput., 2 (1992) 209-220.