These are the sources used by researcher Robert Pate in his article “The Anthrax Mystery: Solved.”
The letters and notes:
Ed Lake, www.anthraxinvestigation.com
“Analysis of the Anthrax Attacks,” by Barbara Hatch Rosenberg, www.fas.org
“Brokaw’s aide tests positive, Suspicious letters to NBC, N.Y. Times sent from St. Petersburg, authorities say,” by David Ballingrud, Mike Brassfield, and Wes Allison, St. Petersburg Times, October 13, 2001.
“Anxious about Anthrax,” by Sharon Begley and Michael Isikoff, Newsweek, October 22, 2001.
“Sorting the Mail, Searching for ‘a Shadow Enemy,’” by Guy Gugliotta, October 28, 2001.
“Anthrax Pervades Florida Site, and Experts See Likeness to That Sent to Senators,” by Andrew C. Revkin and Dana Canedy, New York Times, December 5, 2001.
Graysmith, Robert AMERITHRAX The Hunt for the Anthrax Killer. New York 2003, pages 56, 67,104,105.