Syafaruddin, S.; Bahmani-Oskooee, M.; Tony Sohdin Martua Simanjuntak, E.; Samosir, W.; Delfahedah, Y. STUDY OF CLEAN WATER DISTRIBUTION SERVICES FROM BAHSIKAM SPRINGS IN PDAM TIRTAULI, PEMATANGSIANTAR CITY. IHERT 2020, 2, 269-286.