Authors
Ling-Xiang Liu
Retired from National Metrology Centre of Singapore since Nov. 2008, Berlin, Germany
Zhong-Tai Qian
Retired from National Institute of Metrology, Beijing, China
© 2021 Ling-Xiang Liu, Zhong-Tai Qian, published by Slovak Academy of Sciences, Institute of Measurement Science
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.