EFFECT OF MULTI-GRADE TEACHING ON STUDENTS’ COGNITIVE ABILITIES IN MULTI-GRADE LITERACY CENTERS OF PUNJAB . Pak. j. soc. educ. lang. [Internet]. 2021 Jun. 26 [cited 2026 Apr. 16];7(2):172-81. Available from: https://jehanf.com/pjsel/index.php/journal/article/view/482