@article{MZ_1972__124_171651,
     author = {Ian G. Connell},
     title = {The {Stufe} of {Number} {Fields.}},
     journal = {Mathematische Zeitschrift},
     pages = {20--22},
     year = {1972},
     volume = {124},
     zbl = {0219.12019},
     url = {http://geodesic.mathdoc.fr/item/MZ_1972__124_171651/}
}