“EFFECT OF KELLER SYSTEM OF INSTRUCTION ON FEMALE AND MALE STUDENTS’ ACADEMIC ACHIEVEMENT IN BIOLOGY IN ABAKALIKI EDUCATION ZONE, EBONYI STATE”. JOURNAL OF EDUCATIONAL RESEARCH ON CHILDREN, PARENTS & TEACHERS 6, no. 1 (January 1, 2025): 13–29. Accessed November 8, 2026. https://ercptjournal.com/index.php/ojs/article/view/122.