APA (7th ed.) Citation

May, W. L. (1920). Whorled milkweed: The worst stock-poisoning plant in Colorado. Agricultural Experiment Station of the Agricultural College of Colorado.

Chicago Style (17th ed.) Citation

May, W. L. Whorled Milkweed: The Worst Stock-poisoning Plant in Colorado. Fort Collins, Colo.: Agricultural Experiment Station of the Agricultural College of Colorado, 1920.

MLA (9th ed.) Citation

May, W. L. Whorled Milkweed: The Worst Stock-poisoning Plant in Colorado. Agricultural Experiment Station of the Agricultural College of Colorado, 1920.