HAGEN, Brad; GUNN, Thelma. The Placebo Effect and Learning: Implications for Counsellors. Canadian Journal of Counselling and Psychotherapy, [S. l.], v. 40, n. 4, 2007. Disponível em: https://cdm.ucalgary.ca/index.php/rcc/article/view/58786. Acesso em: 4 jan. 2026.