1. Direct methods for the search of the second invariant;Hietarinta;Phys. Rep.,1987
2. Integrable systems I, In Dynamical Systems IV, Symplectic Geometry and its Applications;Dubrovin,1986
3. Methods of Qualitative Analysis in the Dynamics of a Rigid Body;Kozlov,1980
4. Nonintegrability of Kirchhoff's equations;Kozlov;Sov. Math. Dokl.,1982
5. S.L. Ziglin, Branching of solutions and non-existence of first integrals in Hamiltonian Mechanics, Funct. Anal. Appl. 16 (1983) 181–189, 17 (1983) 6–17.