1. Dick, G. J. Local oscillator induced instabilities in trapped ion frequency standards. In Proc. Precise Time and Time Interval Meeting (ed. Sydnor, R. L.) 133–147 (US Naval Observatory, 1987).
2. Santarelli, G. et al. Frequency stability degradation of an oscillator slaved to a periodically interrogated atomic resonator. IEEE Trans. Ultra. Ferro. Freq. Cont. 45, 887–894 (1998).
3. Dick, G. J., Prestage, J. D., Greenhall, C. A. & Maleki, L. Local oscillator induced degradation of medium-term stability in passive atomic frequency standards. In Proc. 22nd Precise Time and Time Interval Meeting (ed. Sydnor, R. L.) 487–508 (NASA, 1990).
4. Ludlow, A. D., Boyd, M. M., Ye, J., Peik, E. & Schmidt, P. O. Optical atomic clocks. Rev. Mod. Phys. 87, 637–701 (2015).
5. Poli, N., Oates, C. W., Gill, P. & Tino, G. M. Optical atomic clocks. Riv. Nuovo Cimento 36, 555–624 (2013).