TY  - JOUR
AU  - H.H. JOHNSON
TI  - Classical Differential Invariants and Applications to Partial Differential Equations.
JO  - Mathematische Annalen
PY  - 1962
SP  - 308
EP  - 329
VL  - 148
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MAN_1962__148_161000/
ID  - MAN_1962__148_161000
ER  -