%0 Journal Article %A V. V. Petrova %A E. L. Tonkov %T Admissibility of periodic processes and existence theorems for periodic solutions.~I %J Izvestiâ vysših učebnyh zavedenij. Matematika %D 1996 %P 65-72 %N 11 %I mathdoc %U http://geodesic.mathdoc.fr/item/IVM_1996_11_a7/ %G ru %F IVM_1996_11_a7