Verbatim text: Catling, P. M. and K. W. Spicer. 1988. The separation of Betula populifolia and Betula pendula and their status in Ontario. Canad. J. Forest Res. 18: 1017--1026.
Author: Catling, P.M., Spicer, K.W.
Year: 1988
Title: The separation of Betula populifolia and Betula pendula and their status in Ontario
Journal: Canad. J. Forest Res
Volume: 18
Pages: 1017–1026