Heffner, Rickye and Henry Heffner, Hearing in Reptiles, KU# 5939, Correspondence, 1981 - 1983, Box: 42, Folder: 37. University of Kansas Schiefelbusch Institute for Life Span Studies records, RG 35. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/454061 Accessed May 17, 2025.