Verbatim text: Rubtsov, G. A. 1944. Geographical distribution of the genus Pyrus and trends and factors in its evolution. Amer. Midl. Naturalist 78: 358–366.
Author: Rubtsov, G.A.
Year: 1944
Title: Geographical distribution of the genus Pyrus and trends and factors in its evolution
Journal: Amer. Midl. Naturalist
Volume: 78
Pages: 358–366