C.S.S. Rao. Testimony of Lecturers· of Extension Training Centres in Regard. to Effectiveness of Audio- Visuals as Instructional Aids. Indian J Ext Edu [Internet]. 1965 Dec. 1 [cited 2025 Oct. 21];1(3):215-22. Available from: https://epubs.icar.org.in/index.php/IJEE/article/view/159623