@article{PORMA_1980__39_1-4_115419,
     author = {Craveiro de Carvalho, F.J.},
     title = {Transnormal graphs},
     journal = {Portugaliae mathematica},
     pages = {285--287},
     publisher = {mathdoc},
     volume = {39},
     number = {1-4},
     year = {1980},
     mrnumber = {0776241},
     zbl = {0565.57016},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1980__39_1-4_115419/}
}