@article{JRAM_1973__259_151297,
     author = {Urs Kirchgraber},
     title = {Uniform treatment of canonical perturbation theories.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {86--100},
     publisher = {mathdoc},
     volume = {259},
     year = {1973},
     zbl = {0253.70016},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1973__259_151297/}
}