Pakpahan, Romauli, et al. “ THE EFFECT OF CUSTOMER WATER METER CALIBRATION IN CONTROLLING LOSS LEVELS NON-PHYSICAL WATER TIRTAULI PDAM TOZAI INDAH LAMA RESIDENTIAL AREA PEMATANGSIANTAR CITY”. International Conference on Health Science, Green Economics, Educational Review and Technology, vol. 2, Dec. 2020, pp. 1-12, doi:10.54443/ihert.v2i.10.