@article{GDZPPN002326698, title = {Rotation Numbers of Products of Circle Homeomorphisms.}, journal = {Mathematische Annalen}, volume = {270}, year = {1985}, pages = {381-400}, zbl = {0543.57019}, url = {http://dml.mathdoc.fr/item/GDZPPN002326698} }
Neumann, Walter D.; Jankins, Mark. Rotation Numbers of Products of Circle Homeomorphisms.. Mathematische Annalen, Tome 270 (1985) pp. 381-400. http://gdmltest.u-ga.fr/item/GDZPPN002326698/