Ruder, Kenneth, Acquisition of Early Verb Forms, 4048-4, #RR07037, $6,092.00, April 1, 1980-December 31, 1980, Box: 69, Folder: 25. 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/455657 Accessed July 09, 2025.