Amin Khan, Dr. Rehmat Ali Farooq, and Zahoor-ul-Haq. “Effect of Cooperative Learning Approach on Ninth Grade Students’ Achievement in Chemistry”. Research Journal of Social Sciences and Economics Review, Vol. 1, no. 3, Oct. 2020, pp. 247-54, doi:10.36902/rjsser-vol1-iss3-2020(247-254).