Panthai , S., and P. Somboon. “Examination of Separate and Mixed Refi ning Methods on Softwood and Hardwood Pulps for Linerboard Production”. Agriculture and Natural Resources, vol. 48, no. 4, Aug. 2014, pp. 540-7, https://li01.tci-thaijo.org/index.php/anres/article/view/243379.