@article{GDZPPN002298597, title = {Higher Ramification Groups for Rank one Valuations}, journal = {Mathematische Annalen}, volume = {174}, year = {1967}, pages = {253-259}, zbl = {0166.04504}, url = {http://dml.mathdoc.fr/item/GDZPPN002298597} }
Ribenboim, P. Higher Ramification Groups for Rank one Valuations. Mathematische Annalen, Tome 174 (1967) pp. 253-259. http://gdmltest.u-ga.fr/item/GDZPPN002298597/