TY JOUR TI INFLUENCE OF SPRUCE FORESTS DENSITY ON THEIR SANITARY CONDITION KW JO Forestry Engineering Journal AU Ivanchina, L.A. AU Kozhevnikov, A.P. AU Kryazhevskih, N.A. AU Zalesov, S.V. PY 2019 IS 9 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov