1. Unique normal forms for vector fields and Hamiltonians;Baider;J. Differential Equations,1989
2. Unique normal forms for planar vector fields;Baider;Math. Z.,1988
3. Unique normal forms: the Hamiltonian nilpotent case;Baider;J. Differential Equations,1991
4. Versal deformations of a singular point of a vector field on the plane in the case of zero eigenvalues;Bogdanov,1981
5. Bifurcation of a limit cycle for a family of vector fields on the plane;Bogdanov,1981