Columbia subject headings:
Amphibians--North America--Identification.
Amphibians--West (U.S.)--Identification.
Reptiles--North America--Identification.
Reptiles--West (U.S.)--Identification.
Harvard subject headings:
Amphibians--North America--Identification.
Amphibians--West (U.S.)--Identification.
Reference works.
Reptiles--North America--Identification.
Reptiles--West (U.S.)--Identification.
Princeton subject headings: