APA (7th ed.) Citation

Heutte, T., & Shephard, M. (2003). Canada thistle. U.S. Dept. of Agriculture.

Chicago Style (17th ed.) Citation

Heutte, Tom, and Michael Shephard. Canada Thistle. [Washington, D.C.?]: U.S. Dept. of Agriculture, 2003.

MLA (9th ed.) Citation

Heutte, Tom, and Michael Shephard. Canada Thistle. U.S. Dept. of Agriculture, 2003.