APA (7th ed.) Citation

Nixon, E. S., & Cunningham, B. L. (2010). Gymnosperms of the United States & Canada (First edition.). Cunningham.

Chicago Style (17th ed.) Citation

Nixon, Elray S., and Bruce Lyndon Cunningham. Gymnosperms of the United States & Canada. First edition. Nacogdoches, Texas: Cunningham, 2010.

MLA (9th ed.) Citation

Nixon, Elray S., and Bruce Lyndon Cunningham. Gymnosperms of the United States & Canada. First edition. Cunningham, 2010.