N. H. Mohd Sahi and K. Ariffin, “Rubber commodity in Federated Malay States (FMS), 1900-1941: Komoditi getah di Negeri-negeri Melayu Bersekutu (NNMB), 1900-1941”, PERS, vol. 12, no. 2, pp. 1–10, Oct. 2020, doi: 10.37134/perspektif.vol12.2.1.2020.