Coba jelasin Frog calls - Canada dari Anura dong

eastern United States Frog calls - eastern United States

Record UK Frogspawn sightings here  - Springwatch 2006

Frogwatch USA volunteer frog and toad monitoring program by National Wildlife Federation and USGS, includes links to frog calls of the United States

Amphibian photo gallery by scientific name - features many unusual frogs

Scientific American: Researchers Pinpoint Source of Poison Frogs' Deadly Defenses