Verbatim text: Grant, W. F. and B. K. Thompson. 1975. Observations on Canadian birches, Betula cordifolia, B. populifolia, B. papyrifera and B. ×caerulea. Canad. J. Bot. 53: 1478--1490.
Author: Grant, W.F., Thompson, B.K.
Year: 1975
Title: Observations on Canadian birches, Betula cordifolia, B. populifolia, B. papyrifera and B. ×caerulea
Journal: Canad. J. Bot
Volume: 53
Pages: 1478–1490