@article{PORMA_1988__45_4_115636,
     author = {Craveiro de Carvalho, F.J.},
     title = {Projections of transnormal twisted spheres},
     journal = {Portugaliae mathematica},
     pages = {347--349},
     publisher = {mathdoc},
     volume = {45},
     number = {4},
     year = {1988},
     mrnumber = {0982903},
     zbl = {0664.53027},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1988__45_4_115636/}
}