Study Search Results Your query returned 1 results. Series results are grouped under the most relevant study. You can ungroup series results. Use the search box below to revise your search, or start a new search. Results per page: 25 50 100 Sort by: Title A-Z Released/Updated Time Period Most Cited in ICPSR Bib. Most Downloaded (?) Study Title/Investigator 1. School Culture, Climate, and Violence: Safety in Middle Schools of the Philadelphia Public School System, 1990-1994 (ICPSR 2026) Welsh, Wayne N.,; Jenkins, Patricia H.; Greene, Jack R.