@article{10_4153_CJM_2010_053_3,
     author = {Godinho, Leonor},
     title = {The {Fundamental} {Group} of {S} 1-manifolds},
     journal = {Canadian journal of mathematics},
     pages = {1082--1098},
     year = {2010},
     volume = {62},
     number = {5},
     doi = {10.4153/CJM-2010-053-3},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-2010-053-3/}
}