Verbatim text: Wiegrefe, S. J., K. J. Sytsma, and R. P. Guries. 1994. Phylogeny of elms (Ulmus, Ulmaceae): Molecular evidence for a sectional classification. Syst. Bot. 19: 590-612.
Author: Wiegrefe, S.J., Sytsma, K.J., Guries, R.P.
Year: 1994
Title: Phylogeny of elms (Ulmus, Ulmaceae): Molecular evidence for a sectional classification
Journal: Syst. Bot
Volume: 19
Pages: 590–612