1. WHO (2022, May 15). Air Pollution. Available online: https://www.who.int/health-topics/air-pollution.
2. Kamaruddin, S.B. (2022, May 15). UKM Pakarunding Kaji Semula Cara Nilai Kualiti Udara. Available online: https://www.ukm.my/news/Latest_News/ukm-pakarunding-kajli-semula-cara-nilai-kualiti-udara/.
3. Air Pollution Index Trend Analysis in Malaysia, 2010–2015;Rani;Pol. J. Environ. Stud.,2018
4. Malaysian Department of Environment (DOE) (2023, January 20). Pengiraan Indeks Pencemar Udara (IPU), Available online: http://apims.doe.gov.my/pdf/API_Calculation.pdf.
5. Concentrations of Particulate Matter and Their Relationships with Meteorological Variables;Sustain. Environ. Res.,2013