@article{1077473608, author = {Lee, H. C.}, title = {Contact transformations}, journal = {Duke Math. J.}, volume = {13}, number = {1}, year = {1946}, pages = { 161-170}, language = {en}, url = {http://dml.mathdoc.fr/item/1077473608} }
Lee, H. C. Contact transformations. Duke Math. J., Tome 13 (1946) no. 1, pp. 161-170. http://gdmltest.u-ga.fr/item/1077473608/