@article{CMJ_2003__53_2_a6,
     author = {Berrachedi, Abdelhafid and Havel, Ivan and Mulder, Henry Martyn},
     title = {Spherical and clockwise spherical graphs},
     journal = {Czechoslovak Mathematical Journal},
     pages = {295--309},
     publisher = {mathdoc},
     volume = {53},
     number = {2},
     year = {2003},
     mrnumber = {1983453},
     zbl = {1021.05085},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_2003__53_2_a6/}
}