Voir la notice de l'article provenant de la source Czech Digital Mathematics Library
@article{ARM_1976__12_2_a1, author = {Mawhin, Jean}, title = {Contractive mappings and periodically perturbed conservative systems}, journal = {Archivum mathematicum}, pages = {67--73}, publisher = {mathdoc}, volume = {12}, number = {2}, year = {1976}, mrnumber = {0437858}, zbl = {0353.47034}, language = {en}, url = {http://geodesic.mathdoc.fr/item/ARM_1976__12_2_a1/} }
Mawhin, Jean. Contractive mappings and periodically perturbed conservative systems. Archivum mathematicum, Tome 12 (1976) no. 2, pp. 67-73. http://geodesic.mathdoc.fr/item/ARM_1976__12_2_a1/