Heffner, Henry and Rickye Heffner, Hearing in Large Mammals, Correspondence, 1978 - 1982, Box: 42, Folder: 16. 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/454040 Accessed July 08, 2025.