@article{ITA_1986__20_2_191_0, author = {Goral\v{c}{\'\i}k, P. and Goral\v{c}{\'\i}kov\'a, A. and Koubek, V.}, title = {How much semigroup structure is needed to encode graphs ?}, journal = {RAIRO - Theoretical Informatics and Applications - Informatique Th\'eorique et Applications}, pages = {191--206}, publisher = {AFCET - Gauthier-Villars}, address = {Paris}, volume = {20}, number = {2}, year = {1986}, mrnumber = {860769}, zbl = {0601.20053}, language = {en}, url = {http://www.numdam.org/item/ITA_1986__20_2_191_0/} }