@article{MAN_1967__173_161612,
     author = {P. Ribenboim},
     title = {Higher {Ramification} {Groups} for {Rank} one {Valuations}},
     journal = {Mathematische Annalen},
     pages = {253--259},
     publisher = {mathdoc},
     volume = {173},
     year = {1967},
     zbl = {0166.04504},
     url = {http://geodesic.mathdoc.fr/item/MAN_1967__173_161612/}
}