Search Results Use the search box below to revise your search, or start a new search. Studies (1) Variables Publications Your query returned 1 studies. Series results are grouped under the most relevant study. Ungroup series results to view all results. Sort by: Title A-Z Released/Updated Time Period Most Cited in ICPSR Bib. 1. Panel Study of Income Dynamics, 1968-1999: Annual Core Data (ICPSR 7439) Hofferth, Sandra; Stafford, Frank P.; Yeung, Wei-Jun J.; et al.