1. Weijun GAO, and another 6 authors Investigation about the Midterm Operation Effect of the District Energy System at Kitakyushu Science and Research Park. The research report of the Kyushu branch of the society of heating, air-condition and sanitary engineers of Japan volume 10, May, 2003.
2. Hiroshi Matsukawa, Koukichi Koshiishi, Hirotaka Koizumi, Kosuke Kurkawa, Masayasu Hamada, Liu Bo, Dynamic Evaluation of Maximum Power Point Tracking Operation with PV Array Simulator, 12th PVSEC, JEJU, June 11-15 2001.
3. Yamaguchi Tomohik, and another 4 authors, Circumstantiation of the Loss Factor of the PV system by the SV Method, The institute of electrical engineers in Japan, March 2002.