@article{PORMA_1949__8_2_114673,
     author = {Erd\"os, P.},
     title = {On the coefficients of the cyclotomic polynomial},
     journal = {Portugaliae mathematica},
     pages = {63--71},
     publisher = {mathdoc},
     volume = {8},
     number = {2},
     year = {1949},
     mrnumber = {0035787},
     zbl = {0038.01004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1949__8_2_114673/}
}