APA (7th ed.) Citation

Ryan, J. F. (2000). Marigold: Calendula officinalis. Element.

Chicago Style (17th ed.) Citation

Ryan, Joseph F. Marigold: Calendula Officinalis. Shaftesbury ; Boston: Element, 2000.

MLA (9th ed.) Citation

Ryan, Joseph F. Marigold: Calendula Officinalis. Element, 2000.