APA (7th ed.) Citation

Dirr, M. (1997). Dirr's Hardy trees and shrubs: An illustrated encyclopedia. Timber Press.

Chicago Style (17th ed.) Citation

Dirr, Michael. Dirr's Hardy Trees and Shrubs: An Illustrated Encyclopedia. Portland, Or.: Timber Press, 1997.

MLA (8th ed.) Citation

Dirr, Michael. Dirr's Hardy Trees and Shrubs: An Illustrated Encyclopedia. Timber Press, 1997.