Harun Achmad1, - and Sherly Horax, - and Supiaty, - and Arni Irawaty Djais, - and Asmidar Anas, - and Lenny Indirani Hartika, - The Effectiveness of Using Twin Block Functional Appliances and Activators in Class II Malocclusion. Journal of Pharmaceutical Negative Results, 13: issue 4. pp. 939-947.