Qurat-ul-Ain, Iqra ishaq. COMPARISON BETWEEN THE EFFECTIVENESS OF MCKENZIE EXTENSION EXERCISES AND WILLIAM FLEXION EXERCISES FOR TREATMENT OF NON-SPECIFIC LOW BACK PAIN . J. Univ. Med. Dent. Coll. [Internet]. 2017Sep.3 [cited 2025Oct.10];8(3):68-2. Available from: https://www.jumdc.com/index.php/jumdc/article/view/145