@article{10_4153_CJM_1967_059_0,
     author = {Mack, John},
     title = {Directed {Covers} and {Paracompact} {Spaces}},
     journal = {Canadian journal of mathematics},
     pages = {649--654},
     year = {1967},
     volume = {19},
     number = {1},
     doi = {10.4153/CJM-1967-059-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1967-059-0/}
}