@article{05555869, title = {A first order }, journal = {SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]}, volume = {5}, year = {2009}, doi = {10.3842/SIGMA.2009.041}, zbl = {1163.33320}, language = {en}, url = {http://dml.mathdoc.fr/item/05555869} }
Ito, Masahiko. A first order . SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only], Tome 5 (2009) . doi : 10.3842/SIGMA.2009.041. http://gdmltest.u-ga.fr/item/05555869/