1. BIPM 2014 SI Brochure: The International System of Units (SI) [8th edition, 2006; updated in 2014] http://www.bipm.org/en/publications/si-brochure/kelvin.html
2. BIPM 2018 BIPM resolution 1, 26th CGPM 2018 https://www.bipm.org/utils/common/pdf/CGPM-2018/26th-CGPM-Resolutions.pdf
3. BIPM 2014 Consultative Committee for Thermometry http://www.bipm.org/utils/common/pdf/CC/CCT/CCT27.pdf
4. BIPM 2019 Draft Mise en pratique for the definition of the kelvin in the SI https://www.bipm.org/utils/en/pdf/si-mep/MeP-K-2018.pdf
5. Review: the Boltzmann project;Fischer;Metrologia,2018