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@article{SF_1986__33_134801, author = {G.M.S. Gomes}, title = {The lattice of {R-unipotent} congruences on a regular semigroup.}, journal = {Semigroup forum}, pages = {159--174}, publisher = {mathdoc}, volume = {33}, year = {1986}, zbl = {0582.20049}, url = {http://geodesic.mathdoc.fr/item/SF_1986__33_134801/} }
G.M.S. Gomes. The lattice of R-unipotent congruences on a regular semigroup.. Semigroup forum, Tome 33 (1986), pp. 159-174. http://geodesic.mathdoc.fr/item/SF_1986__33_134801/