Voir la notice de l'article provenant de la source Theory and Applications of Categories website
@article{TAC_2014_29_a12, author = {Anders Kock}, title = {Projective lines as groupoids with projection structure}, journal = {Theory and applications of categories}, pages = {371--388}, publisher = {mathdoc}, volume = {29}, year = {2014}, language = {en}, url = {http://geodesic.mathdoc.fr/item/TAC_2014_29_a12/} }
Anders Kock. Projective lines as groupoids with projection structure. Theory and applications of categories, Tome 29 (2014), pp. 371-388. http://geodesic.mathdoc.fr/item/TAC_2014_29_a12/