@article{10_1017_S0017089599970179,
     author = {PRIDE, STEPHEN J.},
     title = {Low dimensional homotopy for monoids {II:} groups},
     journal = {Glasgow mathematical journal},
     pages = {1--11},
     year = {1999},
     volume = {41},
     number = {1},
     doi = {10.1017/S0017089599970179},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089599970179/}
}