1. and : 1968 Joint Convention Record of Four Institutes of Electrical Engineers, Japan, No. 834.
2. and : 1968 Tokyo Section Convention Record of I. E. E., Japan, No. 358.
3. and : 1969 Tokyo Section Convention Record of I. E. E., Japan, No. 345.
4. and : Proc. Cod. on Static Electricity, Japan, No. 11, 1968.
5. et al.: Proc. Cod. on Static Electricity, Japan, No. 13, 1968.