Βαλανίδης Νίκος. “Cognitive Abilities and School Achievement of Lower Secondary School Students: Theoretical and Educational Implications”. Psychology: the Journal of the Hellenic Psychological Society 5, no. 1 (October 15, 2020): 1–19. Accessed June 17, 2024. https://ejournals.epublishing.ekt.gr/index.php/psychology/article/view/24231.