علي شلال أ. ع. . “Measurement of Mental Formation and Human Intelligence ‘A Follow-up Review of Its Origin and Development since 1801 ad’”. مجلة أبحاث الذكاء, vol. 15, no. 32, Aug. 2022, pp. 582-94, https://iru.uomustansiriyah.edu.iq/index.php/intel/article/view/377.