Happiness, self-compassion, and insomnia predicting academic achievement among middle school students with learning difficulty: An optimal function analysis model using Response Surface Methodology. Indian Journal of Clinical Psychology, [S. l.], v. 49, n. 04, 2023. Disponível em: https://ojs.ijcp.co.in/index.php/ijcp/article/view/411.. Acesso em: 31 jan. 2025.