Hojman, Sergio; Pardo, Francisco; Aulestia, Luis; de Lisa, Francisco Lagrangians for differential equations of any order. (English) Zbl 0756.49018 J. Math. Phys. 33, No. 2, 584-590 (1992). Reviewer: M.Degiovanni (Brescia) MSC: 49N45 70H03 PDFBibTeX XMLCite \textit{S. Hojman} et al., J. Math. Phys. 33, No. 2, 584--590 (1992; Zbl 0756.49018) Full Text: DOI
Pardo, Francisco The Helmholtz conditions in terms of constants of motion in classical mechanics. (English) Zbl 0676.70023 J. Math. Phys. 30, No. 9, 2054-2061 (1989). MSC: 70H30 70F99 49S05 PDFBibTeX XMLCite \textit{F. Pardo}, J. Math. Phys. 30, No. 9, 2054--2061 (1989; Zbl 0676.70023) Full Text: DOI