@article{CM_1951__9__241_0,
     author = {Baer, Reinhold},
     title = {The group of motions of a two dimensional elliptic geometry},
     journal = {Compositio Mathematica},
     pages = {241--288},
     publisher = {Kraus Reprint},
     volume = {9},
     year = {1951},
     mrnumber = {48051},
     zbl = {0045.10001},
     language = {en},
     url = {http://www.numdam.org/item/CM_1951__9__241_0/}
}