@article{MZ_1974__140_172145,
     author = {James E. jr. Arnold},
     title = {Chain {Equivalences} and {Schanuel's} {Lemma.}},
     journal = {Mathematische Zeitschrift},
     pages = {245--254},
     year = {1974},
     volume = {140},
     zbl = {0291.55020},
     url = {http://geodesic.mathdoc.fr/item/MZ_1974__140_172145/}
}