Harker, Walter. “Attitudes of Professionals and Non-Professionals Toward the Mentally Retarded in Rio De Janeiro, Brazil”. Revista Interamericana de Psicología/Interamerican Journal of Psychology 3, no. 2 (July 15, 2017). Accessed May 6, 2024. https://journal.sipsych.org/index.php/IJP/article/view/550.