@article{MAN_1985__273_164040,
     author = {Kunio Kaki\'e},
     title = {A {Fundamental} {Property} of {Monge} {Characteristics} in {Involutive} {Systems} of {Non-Linear} {Partial} {Differential} {Equations} and its {Application.}},
     journal = {Mathematische Annalen},
     pages = {89--114},
     publisher = {mathdoc},
     volume = {273},
     year = {1985},
     zbl = {0563.58038},
     url = {http://geodesic.mathdoc.fr/item/MAN_1985__273_164040/}
}