Николаев А.С. On operators commutative with all invariants for harmonics oscillator with commensurable frequencies / А.С.Николаев, 1994. - 9 p. - Текст : непосредственный.
Николаев А.С. On the Diagonalization of the quantum Birkhoff-Gustavson normal form / А.С.Николаев, 1994. - 21 p. - Текст : непосредственный.