5 links
HSUS - Circuses
hsus.org
Collection of articles with reasons to oppose circuses using wild animals. From Humane Society of the United States. Washington DC, US.
IDA - Circus Facts
idausa.org
Travel, pain and public safety issues. From In Defense of Animals. California, US.
NAIA - Animals in Education and Entertainment
naiaonline.org
Includes articles about bans on circus animals. From The National Animal Interest Alliance. Oregon, US.
Outlaw the Animal Circus
AnimalActivism.org
Outlines incidents of circus animal cruelty, undercover investigations, photo gallery and a campaign to ban the exhibition of animal circuses. Based in Australia.
What's Wrong with Circuses and Rodeos?
hedweb.com
From an Animal Rights FAQ (Animals in Entertainment). David Pearce. Brighton, UK.