@article{10_4064_cm_38_1_69_72,
     author = {Harvey Rosen},
     title = {Spanning disks for domains with free fundamental groups},
     journal = {Colloquium Mathematicum},
     pages = {69--72},
     publisher = {mathdoc},
     volume = {38},
     number = {1},
     year = {1977},
     doi = {10.4064/cm-38-1-69-72},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-38-1-69-72/}
}