Zainal Abidin, Mohd Azran, et al. “Pembentukan Indikator Kesihatan Penduduk Bandar Dalam Wilayah Metropolitan Lembah Klang-Langat: An Establishment of Urban Population Health Indicators in Langat-Klang Valley Metropolitan Region”. GEOGRAFI, vol. 2, no. 2, Dec. 2018, pp. 96-114, https://ejournal.upsi.edu.my/index.php/GEOG/article/view/483.