C.S.S. RAO. Testimony of Lecturers· of Extension Training Centres in Regard. to Effectiveness of Audio- Visuals as Instructional Aids. Indian Journal of Extension Education, India, v. 1, n. 3, p. 215–222, 1965. DOI: 10.48165/. Disponível em: https://epubs.icar.org.in/index.php/IJEE/article/view/159623. Acesso em: 21 oct. 2025.