1. Abraham, Ralph and Jerrold E. Marsden [1978], Foundations of Mechanics (Benjamin/Cummings, Reading, Massachusetts).
2. Encyclopedia of Mathematics and its Applications;L. C. Biedenharn,1981
3. Birkho, G. D. [1927], Dynamical Systems, v. IX (AMS Colloquium Publications, New York).
4. Bunker, Philip R. [1979], Molecular Symmetry and Spectroscopy (Academic, New York).
5. Cary, John R. [1981], Lie transforms and their use in Hamiltonian perturbation theory, Phys. Rep. 79, 31–95.