Dadan Prayogo, Bernadus Sadu, Utomo Wicaksono, and Fitri Gunawati, “ADDITION OF DEEP CROSS-FRICTION MASSAGE IS BETTER THAN SLOW STROKE BACK MASSAGE AFTER MCKENZIE EXERCISE TO IMPROVE FUNCTIONAL ABILITY AND WORK PRODUCTIVITY OF STONE BREAKERS WITH NON-SPECIFIC LOW BACK PAIN ”, IJSS, vol. 2, no. 2, pp. 1483–1490, Aug. 2022.