An atomic clock CS2 is pictured in the time-laboratory of the Physical Technical Federal Institution (PTB) in Braunschweig, Germany, 22 October 2012. In the night from 27 to 28 October, the clocks
Caesium atomic clocks from the PTB institute, Lower Saxony, Germany, Brunswick, Lower Saxony, Germany Stock Photo - Alamy
Atomic Clock CS-2 Based on Caesium in the PTB Laboratory, Accuracy 1 Second in 2 Million Years Editorial Photography - Image of institute, physical: 137083597
Opticlock" - die erste transportfähige optische Uhr | BR24
Most accurate and most stable transportable optical clock worldwide - PTB.de
File:Atomuhr-CS2.jpg - Wikimedia Commons
Space, Time and Motion | SpringerLink
Xiaochen Sun's research works | University of Texas Southwestern Medical Center, Texas (UT Southwestern) and other places
Warnings to the general public by means of DCF77 - PTB.de