@article{PORMA_1977__36_1_115295,
     author = {Maloney, John P.},
     title = {A non graph theory approach to {Ulam's} conjecture},
     journal = {Portugaliae mathematica},
     pages = {1--6},
     publisher = {mathdoc},
     volume = {36},
     number = {1},
     year = {1977},
     mrnumber = {0535216},
     zbl = {0435.05049},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1977__36_1_115295/}
}