@article{05555854, title = {Contact geometry of hyperbolic equations of generic type.}, journal = {SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]}, volume = {4}, year = {2008}, doi = {10.3842/SIGMA.2008.058}, zbl = {1173.35320}, language = {en}, url = {http://dml.mathdoc.fr/item/05555854} }
The, Dennis. Contact geometry of hyperbolic equations of generic type.. SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only], Tome 4 (2008) . doi : 10.3842/SIGMA.2008.058. http://gdmltest.u-ga.fr/item/05555854/