USA Department of Agriculture. (1981). Atlas of United States trees. United States Government Printing Office.
Chicago-Zitierstil (17. Ausg.)USA Department of Agriculture. Atlas of United States Trees. Washington, D.C: United States Government Printing Office, 1981.
MLA-Zitierstil (9. Ausg.)USA Department of Agriculture. Atlas of United States Trees. United States Government Printing Office, 1981.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.