A method devised in 1852 to find simple algebraic integrals of motion for Hamiltonian systems with two degrees of freedom.
References
Bertrand, J. J. de Math. 42, 121, 1852.
Whittaker, E. T. A Treatise on the Analytical Dynamics of Particles and Rigid Bodies: With an Introduction to the Problem of Three Bodies. New York: Dover, pp. 331-335, 1944.
