@article{GDZPPN001256505,
title = {Permutable duo semigroups.},
journal = {Semigroup forum},
volume = {30},
year = {1984},
pages = {155-172},
zbl = {0524.20040},
url = {http://dml.mathdoc.fr/item/GDZPPN001256505}
}
Varisco, A.; Cherubini, A. Permutable duo semigroups.. Semigroup forum, Tome 30 (1984) pp. 155-172. http://gdmltest.u-ga.fr/item/GDZPPN001256505/