@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/