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(2) Y. Fujii, O. Oda, Y. Ooura, and T. Kohida: “Development of Aluminum Contact Wire with SteelCore”, Railway Technical Research Report, No. 1300 (1985-8) (in Japanese)
(3) A. Suzuki, A. Ohba, K. Tsuchiya, and T. Kamei: “Development of Compound Trolley Wire (first report)”, Railway Technical Research Report, No. A-86-189 (1986-11) (in Japanese)