Korzikov V. A. RussiaKalugaTsiolkovsky Kaluga State University, 26 Stepan Razina Str., Kaluga 248023, Russiakorzikoff_va@mail.ru Author's articles ON THE NUTRITION OF SOME SEMI-AQUATIC AMPHIBIAN SPECIES (AMPHIBIA: ANURA) IN THE NORTHWESTERN UPPER OKA REGION