@article{GDZPPN002415194, title = {Chain Equivalences and Schanuel's Lemma.}, journal = {Mathematische Zeitschrift}, volume = {136}, year = {1974}, pages = {245-254}, zbl = {0291.55020}, url = {http://dml.mathdoc.fr/item/GDZPPN002415194} }
Arnold, James E. jr. Chain Equivalences and Schanuel's Lemma.. Mathematische Zeitschrift, Tome 136 (1974) pp. 245-254. http://gdmltest.u-ga.fr/item/GDZPPN002415194/