Cryptozoology.com - Thunderbird
- An article by Craig Heinselman discussing the cryptid, sightings, and the elusive "Thunderbird Photograph".
- http://www.cryptozoology.com/cryptids/thunderbird.php

A Comparison of Certain North American Birds to the Thunderbird
- An article by Willie Shughart that compares "five of the largest birds to occur in the contiguous United States and southern Canada" to the thunderbird.
- http://cryptosquared.tripod.com/insights/tbirdcomp.html

Evidence of the Giant Birds
- Evidence that the Native Americans legend of the thunderbird is based on fact.
- http://sped2work.tripod.com/evidence.html