@article{JRAM_1971__251_151166,
     author = {Rudolf Borges},
     title = {Valuations and {M\"obius} {Function.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {181--192},
     publisher = {mathdoc},
     volume = {251},
     year = {1971},
     zbl = {0346.06010},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1971__251_151166/}
}