Udem, Thomas Laser Spectroscopy, Max Planck Institute of Quantum Optics, Max Planck Society;
Udem, T., & Riehle, F. (2007). Frequency combs applications and optical frequency standards (reprinted from Proceedings of the International School of Physics "Enrico Fermi" Course CLXVI "Metrology and Fundamental Constants" pg 317-365, 2007). Rivista del Nuovo Cimento, 30(12), 563-606.