Otto, Dr. David to Xuan Thuy regarding delegation traveling to Paris, France, November 25, 1970, Box: 1, Page: 1. The Dr. David A. Otto, Special Envoy for the Missouri State Teachers Association during the time of the 1971 Paris Peace Talks, collection, RH MS 1257. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/32485 Accessed May 16, 2024.