APA (7th ed.) Citation

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

Chicago Style (17th ed.) Citation

Thomson, Robert Boyd, 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.

MLA (9th ed.) Citation

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

Warning: These citations may not always be 100% accurate.