APA (7th ed.) Citation

Helms. (1998). The DICTIONARY of forestry. The Society of American Foresters.

Chicago Style (17th ed.) Citation

Helms. The DICTIONARY of Forestry. Bethesda, MD: The Society of American Foresters, 1998.

MLA (9th ed.) Citation

Helms. The DICTIONARY of Forestry. The Society of American Foresters, 1998.