TY JOUR TI Minimum possible sample timber for research KW wood KW early KW late KW diffuse-porous KW ringed KW ontogeny KW tracheid KW core density. JO Actual directions of scientific researches of the XXI century: theory and practice AU Kosichenko, N.E. PY 2014 IS 2 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov