W.C. Chee, W.S. Ho, H. Hashim, M.A. Zubir, L.K. Lim, Z. Ab Muis, K.Y. Wong, M.R. Taib, A.A. Mustaffa, Carbon and Economic Analysis on Cogeneration Natural Gas Boiler and Solar Photovoltaic in Pulp and Paper Industry, Chemical Engineering Transactions. 97 (2022) 505-510. doi:10.3303/CET2297085.