@article{CMUC_1983_24_3_a11,
     author = {Havel, V\'aclav},
     title = {Replaceable nets and improper collineations},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {507--517},
     year = {1983},
     volume = {24},
     number = {3},
     mrnumber = {730146},
     zbl = {0541.51002},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1983_24_3_a11/}
}