@article{GDZPPN00125314X, title = {Quasi resolved semigroups and quintets.}, journal = {Semigroup forum}, volume = {18}, year = {1979}, pages = {267-278}, zbl = {0407.20057}, url = {http://dml.mathdoc.fr/item/GDZPPN00125314X} }
Krishnan, V.S. Quasi resolved semigroups and quintets.. Semigroup forum, Tome 18 (1979) pp. 267-278. http://gdmltest.u-ga.fr/item/GDZPPN00125314X/