@article{AUCMP_2009__50_1_a5, author = {Trch, Milan}, title = {Groupoids and the associative law {IIIA.} {(Primitive} extensions of {SH-groupoids} and their semigroup distances)}, journal = {Acta Universitatis Carolinae. Mathematica et Physica}, pages = {73--82}, publisher = {mathdoc}, volume = {50}, number = {1}, year = {2009}, mrnumber = {2569470}, zbl = {1181.20062}, language = {en}, url = {https://geodesic-test.mathdoc.fr/item/AUCMP_2009__50_1_a5/} }