@article {2813, title = {Partial transformation monoids preserving a uniform partition}, journal = {Semigroup Forum (DOI 10.1007/s00233-014-9629-5)}, volume = {90}, year = {2015}, pages = {532-544}, abstract = {

The objective of this paper is to study the monoid of all partial
transformations of a finite set that preserve a uniform partition. In addition
to proving that this monoid is a quotient of a wreath product with respect to a
congruence relation, we show that it is generated by 5 generators, we compute
its order and determine a presentation on a minimal generating set.

}, url = {http://link.springer.com/article/10.1007/s00233-014-9629-5}, author = {Cical{\`o}, Serena and Fernandes, V{\'\i}tor H. and Schneider, Csaba} }