APA (7th ed.) Citation

Helmer, M. J. C., & Decker, K. S. (1991). Pictorial guide to perennials. Merchants Pub. Co..

Chicago Style (17th ed.) Citation

Helmer, M. Jane Coleman, and Karla S. Decker. Pictorial Guide to Perennials. Kalamazoo, Mich.: Merchants Pub. Co., 1991.

MLA (9th ed.) Citation

Helmer, M. Jane Coleman, and Karla S. Decker. Pictorial Guide to Perennials. Merchants Pub. Co., 1991.