NORMAL FORM METHOD IN SEARCH FOR PERIODIC SOLUTIONS OF ORDINARY DIFFERENTIAL EQUATIONS. CASE OF THE FOURTH ORDER Article Edneral V.F., Timofeevskaya O.D. Informatsionno-Upravliaiushchie Sistemy Information and Control Systems. Saint Petersburg State University of Aerospace Instrumentation. Vol. 2018. 2018. P. 24-34
SEARCHING FOR INTEGRALS OF MOTION OF ONE CASE OF HILL'S SYSTEM Article Batkhin A.B., Edneral V.F., Timofeevskaya O.D. 17th Workshop on Computer Algebra, May 21-22, 2014, Dubna. [б.и.]. 2014. P. 1-1