@article{10_4064_fm223_2_2,
     author = {Gerhard Dorfer and J\"org M. Thuswaldner and Reinhard Winkler},
     title = {Fundamental groups of one-dimensional spaces},
     journal = {Fundamenta Mathematicae},
     pages = {137--169},
     publisher = {mathdoc},
     volume = {223},
     number = {2},
     year = {2013},
     doi = {10.4064/fm223-2-2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm223-2-2/}
}