@article{CMUC_1960__1_1_a0,
     author = {\v{C}ech, Eduard},
     title = {Propri\'et\'es projectives du contact. {III}},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {1--19},
     publisher = {mathdoc},
     volume = {01},
     number = {1},
     year = {1960},
     zbl = {0116.13801},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1960__1_1_a0/}
}