Study Search Results Your query returned 2 results. Series results are grouped under the most relevant study. You can ungroup series results. Results per page: 25 50 100 Sort by: Study Relevance Title A-Z Released/Updated Time Period Most Cited in ICPSR Bib. Variable Relevance (?) Study Title/Investigator 1. Study of Dementia in Swedish Twins, 1990-1999 (ICPSR 25963) Gatz, Margaret; Pedersen, Nancy 2. Swedish Adoption/Twin Study on Aging (SATSA), 1984, 1987, 1990, and 1993 (ICPSR 3843) Pedersen, Nancy L.