principe variationnel
1994 / Variational principles of irreversible processes / Masakazu Ichiyanagi / Physics Reports 243 (1994) p. 125 [doi]
1996 / Direct use of variational principles as an approximation technique in classical mechanics / C. G. Gray ; G. Karl ; V. A. Novikov / American Journal of Physics 64 (1996) p. 1177 [doi]