A guide to the poisonous plants and weed seeds of Canada and the northern United States,
by R. B. Thomson and H. B. Sifton.

APA Citation

Thomson, R. Boyd., Sifton, H. Boyd. (1922). A guide to the poisonous plants and weed seeds of Canada and the northern United States. [Toronto]: University of Toronto Press.

MLA Citation

Thomson, Robert Boyd, 1870-, and Harold Boyd Sifton. A Guide to the Poisonous Plants And Weed Seeds of Canada And the Northern United States. [Toronto]: University of Toronto Press, 1922.

Warning: These citations may not always be complete (especially for serials).