Powell, A. M. (1988). Trees & shrubs of Trans-Pecos Texas: Including Big Bend and Guadalupe Mountains National Parks. Big Bend Natural History Assoc.
Chicago-Zitierstil (17. Ausg.)Powell, A. Michael. Trees & Shrubs of Trans-Pecos Texas: Including Big Bend and Guadalupe Mountains National Parks. Big Bend National Park: Big Bend Natural History Assoc, 1988.
MLA-Zitierstil (9. Ausg.)Powell, A. Michael. Trees & Shrubs of Trans-Pecos Texas: Including Big Bend and Guadalupe Mountains National Parks. Big Bend Natural History Assoc, 1988.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.