9Yukio Nakano, Yoshitaka Sunaga. Availability of corona cage for predicting audible noise generated from HVDC transmission line [J]. IEEE Trans on PWRD, 1989, 4(Z) : 1422-1431.
10Yukio Nakano, Yoshitaka Sunaga. Availability of corona cage for predicting radio interference generated from HVDC transmission line [J]. IEEE Trans on PWRD, 1990, 5(3): 1436- 1442.