1. Rattlesnake bite victims showing extreme symptoms;Myers;Associated Press,2008
2. Is rattlesnake's bite growing deadlier?;Nolan;The Arizona Republic,2008
3. Snakebites becoming more toxic;Warth;North County Times,2008
4. Is rattlesnake venom evolving?;Grenard;Nat Hist (Am Mus Nat Hist.),2000