@article{JRAM_1975__273_151558,
     author = {P. Erd\"os and G.J. Rieger},
     title = {Ein {Nachtrag} \"uber befreundete {Zahlen.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {220--220},
     publisher = {mathdoc},
     volume = {273},
     year = {1975},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1975__273_151558/}
}