@article{PORMA_1988__45_4_115635,
     author = {Cordovil, Ra\'ul and Guedes de Oliveira, A. and Moreira, M. Leonor},
     title = {Parallel projection of matroid spheres},
     journal = {Portugaliae mathematica},
     pages = {337--346},
     publisher = {mathdoc},
     volume = {45},
     number = {4},
     year = {1988},
     mrnumber = {0982902},
     zbl = {0676.05030},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1988__45_4_115635/}
}