Gaeta, Giuseppe Symmetry and periodic solutions of nonlinear dynamical systems. (English) Zbl 0744.58063 Nonlinear dynamics, Proc. Conf., Bologna/Italy 1988, 344-348 (1989). Reviewer: F.Neuman (Brno) MSC: 37G99 37C80 34C25 PDFBibTeX XMLCite \textit{G. Gaeta}, in: Conference on nonlinear dynamics, Bologna, Italy, 30 May-3 June 1988. Singapore etc.: World Scientific. 344--348 (1989; Zbl 0744.58063)
Cicogna, G. Breaking symmetries in nonlinear dynamic problems. (English) Zbl 0744.58055 Nonlinear dynamics, Proc. Conf., Bologna/Italy 1988, 242-247 (1989). Reviewer: F.Neuman (Brno) MSC: 37G99 37C80 PDFBibTeX XMLCite \textit{G. Cicogna}, in: Conference on nonlinear dynamics, Bologna, Italy, 30 May-3 June 1988. Singapore etc.: World Scientific. 242--247 (1989; Zbl 0744.58055)
Toland, J. F. A homotopy invariant for dynamical systems with a first integral. (English) Zbl 0703.58049 Ordinary and partial differential equations, Vol. II, Proc. 10th Dundee Conf., Dundee/UK 1988, Pitman Res. Notes Math. Ser. 216, 204-217 (1989). Reviewer: A.Vanderbauwhede MSC: 37G99 37C80 PDFBibTeX XML
Krasil’shchik, I. S.; Vinogradov, A. M. Nonlocal trends in the geometry of differential equations: Symmetries, conservation laws, and Bäcklund transformations. (English) Zbl 0692.35003 Acta Appl. Math. 15, No. 1-2, 161-209 (1989). MSC: 35A30 35G20 35F20 58J10 58J70 58H05 58J72 PDFBibTeX XMLCite \textit{I. S. Krasil'shchik} and \textit{A. M. Vinogradov}, Acta Appl. Math. 15, No. 1--2, 161--209 (1989; Zbl 0692.35003) Full Text: DOI