@article{10_4064_fm220_2_5,
     author = {Stefan Geschke},
     title = {Clopen graphs},
     journal = {Fundamenta Mathematicae},
     pages = {155--189},
     publisher = {mathdoc},
     volume = {220},
     number = {2},
     year = {2013},
     doi = {10.4064/fm220-2-5},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm220-2-5/}
}