Efriza, E., and Z. Zulmiyetri. “Improving Vocational Ability To Grow Hydroponics Through Direct Learning Models For Children With Light Mental Retardation”. EDUCATIO : Journal of Education, Vol. 4, no. 2, Nov. 2019, pp. 184-91, http://ejournal.staimnglawak.ac.id/index.php/educatio/article/view/184.