The cardinal and the idempotent number of various monoids of transformations on a finite chain." *Bulletin of the Malaysian Mathematical Sciences Society*. 34.2 (2011): 79-85. Abstract

"On the monoids of transformations that preserve the order and a uniform partition." *Communications in Algebra*. 39.8 (2011): 2798-2815.

"Bilateral semidirect product decompositions of transformation monoids." *Semigroup Forum*. 82 (2011): 271-287. Abstract

"Endomorphisms of the semigroup of order-preserving mappings." *Semigroup Forum*. 81 (2010): 277-285.Website

"On divisors of semigroups of order-preserving mappings of a finite chain." *Semigroup Forum*. 81 (2010): 551-554.Website

"Congruences on monoids of transformations preserving the orientation of a finite chain." *J. Algebra*. 321 (2009): 743-757.Website

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On divisors of pseudovarieties generated by some classes of full transformation semigroups." *Algebra Colloq.*. 15 (2008): 581-588.

"Largest 2-generated subsemigroups of the symmetric inverse semigroup." *Proc. Edinb. Math. Soc. (2)*. 50 (2007): 551-561.Website

"Relative abelian kernels of some classes of transformation monoids." *Bull. Austral. Math. Soc.*. 73 (2006): 375-404.Website

"Congruences on monoids of order-preserving or order-reversing transformations on a finite chain." *Glasg. Math. J.*. 47 (2005): 413-424.Website

"Presentations for some monoids of partial transformations on a finite chain." *Comm. Algebra*. 33 (2005): 587-604.Website

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Abelian kernels of monoids of order-preserving maps and of some of its extensions." *Semigroup Forum*. 68 (2004): 335-356.Website

"Abelian kernels, solvable monoids and the abelian kernel length of a finite monoid." *Semigroups and languages*. World Sci. Publ., River Edge, NJ, 2004. 68-85.

"Presentations for some monoids of injective partial transformations on a finite chain." *Southeast Asian Bull. Math.*. 28 (2004): 903-918.

"On semigroups whose idempotent-generated subsemigroup is aperiodic." *Internat. J. Algebra Comput.*. 14 (2004): 655-665.Website

"Presentations for some monoids of partial transformations on a finite chain: a survey." *Semigroups, algorithms, automata and languages (Coimbra, 2001)*. World Sci. Publ., River Edge, NJ, 2002. 363-378.

"A new class of divisors of semigroups of isotone mappings of finite chains." *Izv. Vyssh. Uchebn. Zaved. Mat.* (2002): 51-59.

"A division theorem for the pseudovariety generated by semigroups of orientation preserving transformations on a finite chain." *Comm. Algebra*. 29 (2001): 451-456.Website

"The monoid of all injective order preserving partial transformations on a finite chain." *Semigroup Forum*. 62 (2001): 178-204.

"On generators and relations for unions of semigroups." *Semigroup Forum*. 63 (2001): 49-62.

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