S. Mahitthimahawong, . N. . Chaiwattanapong, T. . Paterson, and . T. . Srinophakun, “Passivity-based Proportional Integral Tuning Method for a Simple Heat Exchanger Network”, Agr. Nat. Resour., vol. 48, no. 4, pp. 651–664, Aug. 2014.