Cromwell, R., MZ and DZ Concordance among Schizophrenic Related Phenotypes, KU# 5620, Correspondence,, 1992 - 1993, Box: 20, Folder: 22. 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/452807 Accessed May 19, 2025.