Ruder, Ken and Joanne Pickar, Early Social Interaction: A Study of Speech Acts, BEH GOO7900015, KU# 4904, Final Report, November, 1980, Box: 69, Folder: 35. 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/455667 Accessed May 22, 2025.