1. The theory of compatibility and methods of integrating systems of non-linear partial differential equations;Yanenko,1964
2. The Method of Differential Constraints and its Applications in Gas Dynamics;Sidorov,1984
3. Les Systèmes Différentiels Extérieurs et Leurs Applications Geometriques;Cartan,1945
4. The Cartan Method of Exterior Forms in Differential Geometry;Finikov,1948
5. Lectures on Involutive Systems of Partial Differential Equations;Kuranishi,1967