@article{GDZPPN00206152X, title = {Commutators of Diffeomorphisms}, journal = {Commentarii mathematici Helvetici}, volume = {49}, year = {1974}, pages = {512-528}, zbl = {0289.57014}, url = {http://dml.mathdoc.fr/item/GDZPPN00206152X} }
Mather, John N. Commutators of Diffeomorphisms. Commentarii mathematici Helvetici, Tome 49 (1974) pp. 512-528. http://gdmltest.u-ga.fr/item/GDZPPN00206152X/