S. I. Shahizam, N. Z. Abd Hamid, and S. Side, “Forecasting Carbon Monoxide (CO) Pollutant in Putrajaya using the Local Mean Approximation Method: Peramalan Bahan Pencemar Karbon Monoksida (CO) di Putrajaya Menggunakan Kaedah Penghampiran Purata Setempat”, J. Sci. Math. Lett., vol. 9, pp. 63–71, Feb. 2021, doi: 10.37134/jsml.vol9.sp.8.2021.