LENS, W.; PAIXÃO, M. P.; HERRERA, D. Instrumental Motivation is Extrinsic Motivation: So What???. Psychologica, [S. l.], n. 50, p. p. 21-40, 2009. DOI: 10.14195/1647-8606_50_2. Disponível em: https://impactum-journals.uc.pt/psychologica/article/view/1647-8606_50_2. Acesso em: 4 jun. 2025.