@article{CLTM_1968_1968_1_a4,
     author = {Archidiacono, Giuseppe},
     title = {L'Universo di de {Sitter} e la relativita proiettiva.},
     journal = {Collectanea mathematica},
     pages = {51-71},
     publisher = {mathdoc},
     volume = {19},
     number = {1-2},
     year = {1968},
     url = {http://geodesic.mathdoc.fr/item/CLTM_1968_1968_1_a4/}
}