@article{02104405, title = {The braid groups of the projective plane.}, journal = {Geometry \& Topology}, volume = {8}, year = {2004}, pages = {757-780}, doi = {10.2140/agt.2004.4.757}, zbl = {1056.20024}, language = {en}, url = {http://dml.mathdoc.fr/item/02104405} }
Gonçalves, Daciberg Lima; Guaschi, John. The braid groups of the projective plane.. Geometry & Topology, Tome 8 (2004) pp. 757-780. doi : 10.2140/agt.2004.4.757. http://gdmltest.u-ga.fr/item/02104405/