Okan , Merve, et al. “Stacked Generalization Model for Predicting Happiness: Positive Affect, Gratitude, Social Connectedness, and Psychological Flexibility”. Journal of Assessment and Research in Applied Counseling (JARAC), vol. 8, no. 3, July 2026, pp. 1-10, https://www.journals.kmanpub.com/index.php/jarac/article/view/207.