Usoltsev V. А., A. Piernik, A. A. Osmirko, I. S. Tsepordey, V. P. Chasovskikh, and W. Zukow. “Forest Stand Biomass of Picea spp.: An Additive Model That May Be Related to Climate and Civilisational Changes”. Bulletin of Geography. Socio-Economic Series, vol. 45, no. 45, Sept. 2019, pp. 133-47, doi:10.2478/bog-2019-0029.