APA (7th ed.) Citation

Clausen, R. R., & Christopher, T. (2015). Essential perennials: The complete reference to 2700 perennials for the home garden. Timber Press.

Chicago Style (17th ed.) Citation

Clausen, Ruth Roger, and Thomas Christopher. Essential Perennials: The Complete Reference to 2700 Perennials for the Home Garden. Portland: Timber Press, 2015.

MLA (9th ed.) Citation

Clausen, Ruth Roger, and Thomas Christopher. Essential Perennials: The Complete Reference to 2700 Perennials for the Home Garden. Timber Press, 2015.