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@article{ADM_2013_16_1_a12, author = {E. D. Schwab}, title = {Inverse semigroups generated by group congruences. {The} {M\"{o}bius} functions}, journal = {Algebra and discrete mathematics}, pages = {116--126}, publisher = {mathdoc}, volume = {16}, number = {1}, year = {2013}, language = {en}, url = {http://geodesic.mathdoc.fr/item/ADM_2013_16_1_a12/} }
E. D. Schwab. Inverse semigroups generated by group congruences. The M\"{o}bius functions. Algebra and discrete mathematics, Tome 16 (2013) no. 1, pp. 116-126. http://geodesic.mathdoc.fr/item/ADM_2013_16_1_a12/