@article{CMUC_1973_14_4_a4,
     author = {Moran, Daniel A.},
     title = {Minimal cell coverings of some sphere bundles},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {647--650},
     year = {1973},
     volume = {14},
     number = {4},
     mrnumber = {0331383},
     zbl = {0266.55011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1973_14_4_a4/}
}