TUIJNMAN, A. Selection bias in program impact evaluation research. Aikuiskasvatus, [S. l.], v. 8, n. 4, p. 11–, 1988. DOI: 10.33336/aik.96581. Disponível em: https://journal.fi/aikuiskasvatus/article/view/96581. Acesso em: 17 jul. 2024.