Nwobasi Chukwudi Samuel & Nwani Pius Okorie. VIDEOTAPE INSTRUCTIONAL PACKAGE AND ITS EFFECT ON STUDENTS’ ACHIEVEMENT AND RETENTION OF CONCEPTS IN CHEMISTRY AT SECONDARY SCHOOLS. IJRSM [Internet]. 2020 Oct. 30 [cited 2024 Dec. 22];7(10):1-9. Available from: http://ijrsm.com/index.php/journal-ijrsm/article/view/151