1. (1) T. Minakawa: “Technological Renovation on Electric Utilities in USA (No. 3),” Technology Bulletin of Tohoku Electric Power Co., No. 35 (1971) (in Japanese)
2. (2) T. Minakawa, Y. Ichikawa, S. Hayashi, K. Hirayama, T. Sogabe, and T. linebreak Toyozumi: “Limiting the movements of transformer taps to control voltage and reactive power”, 11th PSCC, Avignon, France (1993)
3. (3) S. Hayashi, K. Hirayama, T. Sogabe, T. Toyozumi, T. Minakawa, and Y. Ichikawa: “Fuzzy expert for main transformer's tap Changer to control voltage and reactive power”, T. IEE Japan, Vol. 115-B, No. 11, pp. 1337-1442 (1995-11)
4. (4) H. Lerebvre, D. Fragnier, J. Boussion, P. Mallet, and M. Bulot: “Advantages of Coordinated Secondary Voltage Control in a Deregulated Environment”, CIGRE, Report 39-208 (2000)
5. (5) T. Minakawa, R. Yokoyama, E. Momma, and J. Sugimoto: “Advanced autonomous transformer's tap changer control sysyem for coordinated secondary voltage control in EHV power systems”, Catalog No. 03EX719C, ISBN 0-7803-7967-5/03/ (CDROM), 2003 IEEE Bologna Power Tech, Bologna, Italy (2003-6)