C.
Sanner
Sanner, C. ., Huntemann, N. ., Lange, R. ., Tamm, C. ., Peik, E. ., Safronova, M. S., & Porsev, S. G. (2019). Optical clock comparison for Lorentz symmetry testing. Nature, 567, 204-+. http://doi.org/10.1038/s41586-019-0972-2
Safronova, M. S., Porsev, S. G., Sanner, C. ., & Ye, J. . (2018). Two Clock Transitions in Neutral Yb for the Highest Sensitivity to Variations of the Fine-Structure Constant. Physical Review Letters, 120. http://doi.org/10.1103/PhysRevLett.120.173001