Cromwell, R., MZ and DZ Concordance among Schizophrenic Related Phenotypes, KU# 5620, March 15, 1993, Box: 20, 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/452810 Accessed May 15, 2025.