Judkins, David, Douglas Walton, Gabriel Durham, Daniel Litwok, and Samuel Dastrup (2021). Still bridging the opportunity divide for low-income youth: Year Up’s longer-term impacts, technical appendices, OPRE Report #2021-56, Washington, DC: Office of Planning, Research, and Evaluation, Administration for Children and Families, U.S. Department of Health and Human Services. Available at https://www.acf.hhs.gov/sites/default/files/documents/opre/year-up-appendices-april-2021.pdf