@article{MZ_1967__96_170665,
     author = {U. Krengel and H. Michel},
     title = {\"Uber {Wurzeln} ergodischer {Transformationen.}},
     journal = {Mathematische Zeitschrift},
     pages = {50--57},
     publisher = {mathdoc},
     volume = {96},
     year = {1967},
     zbl = {0153.08403},
     url = {http://geodesic.mathdoc.fr/item/MZ_1967__96_170665/}
}