Николаев Е.В. Periodic motions in systems with a finite symmetry group : Preprint / Е.В.Николаев, 1994. - 29 p. - Текст : непосредственный.
Николаев Е.В. Geometrical features of a vector field with an involution built-in and bifurcations of a symmetric limit cycle / Е.В.Николаев, 1993. - 16 p. - Текст : непосредственный.