Mahitthimahawong, Siwaporn, Nitipat Chaiwattanapong, Tony Paterson, and Thongchai Srinophakun. 2014. “Passivity-Based Proportional Integral Tuning Method for a Simple Heat Exchanger Network”. Agriculture and Natural Resources 48 (4). Bangkok, Thailand:651-64. https://li01.tci-thaijo.org/index.php/anres/article/view/243392.