Vinogradov, A. M. Geometry of nonlinear differential equations. (English) Zbl 0475.58025 J. Sov. Math. 17, 1624-1649 (1981). MSC: 58J99 35A99 58A20 58A30 58J70 58-02 PDF BibTeX XML Cite \textit{A. M. Vinogradov}, J. Sov. Math. 17, 1624--1649 (1981; Zbl 0475.58025) Full Text: DOI
Vinogradov, A. M. Geometry of non-linear differential equations. (Russian) Zbl 0461.58012 Itogi Nauki Tekh., Ser. Probl. Geom. 11, 89-134 (1980). MSC: 58Jxx 58-02 PDF BibTeX XML