Columbia subject headings:
Captive wild animals--United States.
Endangered species--United States.
Wild animal trade--United States.
Wildlife conservation--Study and teaching--Activity programs--United States.
Zoology--Study and teaching--Activity programs--United States.
Harvard subject headings:
Captive wild animals--United States.
Endangered species--United States
Wild animal trade--United States.
Wildlife conservation--Study and teaching--Activity programs--United States.
Zoology--Study and teaching--Activity programs--United States.
Princeton subject headings: