APA (7th ed.) Citation

Shigo, A. L. (1989). A new tree biology: Facts, photos, and philosophies on trees and their problems and proper care (2nd ed.). Shigo & Trees.

Chicago Style (17th ed.) Citation

Shigo, Alex L. A New Tree Biology: Facts, Photos, and Philosophies on Trees and Their Problems and Proper Care. 2nd ed. Durham, New Hampshire, USA: Shigo & Trees, 1989.

MLA (9th ed.) Citation

Shigo, Alex L. A New Tree Biology: Facts, Photos, and Philosophies on Trees and Their Problems and Proper Care. 2nd ed. Shigo & Trees, 1989.