surinya, T. (1985). The study on the Relationship Between Intelligence Quotient Obtained from the Coloured Progressive Matrices and Piaget’s Theory on the stages of Cognitive Development of Thai Children, Age 5-11 Years. Kasetsart Journal of Social Sciences, 6(2), 135–139. retrieved from https://so04.tci-thaijo.org/index.php/kjss/article/view/243558