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2. Lai CH, Phang WL and Chan NW 2013c A study of non-revenue water management in Penang as an example of good water governance Seminar Hasil Penyelidikan Sektor Pengajian Tinggi Ke-3, Universiti Utara Malaysia, Kedah.
3. Asian Development Bank (ADB) 2010 Every drop counts: learning from good practice in eigth asian cities Asian Development Bank, Mandaluyong City, Philippines.
4. Frauendorfer R and Liemberger R 2010 The issues and challenges of reducing non-revenue water Asian Development Bank. Philippines.
5. AWER 2012 Loss of Income Due to Non-Revenue Water (Estimated Non-Revenue Water) Estimated At RM1.74 Billion For 2010 https://www.awer.org.my