@article{MS2_1958__6_165680,
     author = {Anton Jensen},
     title = {On the {Homotopy} {Structure} of {Coverings.}},
     journal = {Mathematica Scandinavica},
     pages = {137--159},
     publisher = {mathdoc},
     volume = {6},
     year = {1958},
     zbl = {0089.17903},
     url = {http://geodesic.mathdoc.fr/item/MS2_1958__6_165680/}
}