National Survey of Adoptive Parents:
Chapin Hall Center for Children: a research center at the University of Chicago that produces policy-related research on child welfare and foster care.
Donaldson Adoption Institute: an independent and objective adoption research and policy organization whose website contains research reports on a range of adoption topics.
Primary longitudinal studies related to adoption:
National Survey of Child & Adolescent Well-being
Minnesota-Texas Adoption Research Project
Early Growth and Development Study
National Survey of Family Growth
Leiden Longitudinal Adoption Study