@article{1183497368, author = {Thomas, J. M.}, title = {An existence theorem for generalized pfaffian systems}, journal = {Bull. Amer. Math. Soc.}, volume = {40}, number = {12}, year = {1934}, pages = { 309-315}, language = {en}, url = {http://dml.mathdoc.fr/item/1183497368} }
Thomas, J. M. An existence theorem for generalized pfaffian systems. Bull. Amer. Math. Soc., Tome 40 (1934) no. 12, pp. 309-315. http://gdmltest.u-ga.fr/item/1183497368/