@article{MAN_1981__256_163503,
     author = {David F. Anderson and Jack Ohm},
     title = {Valuations and {Semi-Valuations} of {Graded} {Domains.}},
     journal = {Mathematische Annalen},
     pages = {145--156},
     publisher = {mathdoc},
     volume = {256},
     year = {1981},
     zbl = {0442.13002},
     url = {http://geodesic.mathdoc.fr/item/MAN_1981__256_163503/}
}