@article{CLTM_1999_1999_1_a9,
     author = {Spaggiari, Fulvia},
     title = {Sobre el g\'enero de {RP3} x {S1.}},
     journal = {Collectanea mathematica},
     pages = {229-241},
     publisher = {mathdoc},
     volume = {50},
     number = {3},
     year = {1999},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CLTM_1999_1999_1_a9/}
}