1. (1) Y. Sakamoto : “DC Voltage Standard”, J. Japan Society Precision Engineering, Vol. 66, No. 11, pp. 1618-1621 (2000) (in Japanese)
2. (2) “Chapter 9 : DC Ratio” in FLUKE : Calibration : Philosophy in Practice, 2nd Edition, pp. 9_1-9_22 (1994)
3. (3) Guildline “Calibration procedure”, Technical Manual for Model 9700PL Standard Volt Ratio Box, pp. 4_2-4_3 (1980)
4. (4) “General requirements for the competence of testing and calibration laboratories”, ISO/IEC 17025 (1999)
5. (5) FLUKE “Introduction and Specifications”, 752A Reference Divider, p. 1_1(1983)