@article{MZ_1971__122_171593,
     author = {Guido Karrer},
     title = {Algebraische {Operationen} auf {Faserb\"undeln.}},
     journal = {Mathematische Zeitschrift},
     pages = {177--188},
     publisher = {mathdoc},
     volume = {122},
     year = {1971},
     zbl = {0219.55014},
     url = {http://geodesic.mathdoc.fr/item/MZ_1971__122_171593/}
}