The valve-maintained tuning-fork as a precision time-standard.

[1] Abraham H, 1919, CR HEBD ACAD SCI, V168, P1105

[2] BUTTERWORTH S, 1920, PHY SOC P, V33, P345

[3] Eccles WH, 1919, P PHYS SOC LOND, V31, P269

[4] Eccles WH, 1919, P PHYS SOC LOND, V31, P151

[5] ECKHARDT EA, 1921, PHYS REV, V17, P535

[6] ECKHARDT EA, 1922, J FRANKLIN I, V174, P61

[1] Abraham H, 1919, CR HEBD ACAD SCI, V168, P1105

[2] BUTTERWORTH S, 1920, PHY SOC P, V33, P345

[3] Eccles WH, 1919, P PHYS SOC LOND, V31, P269

[4] Eccles WH, 1919, P PHYS SOC LOND, V31, P151

[5] ECKHARDT EA, 1921, PHYS REV, V17, P535

[6] ECKHARDT EA, 1922, J FRANKLIN I, V174, P61