1. Mise en pratique for the definition of the kelvin. http://www.bipm.org/utils/en/pdf/MeP_K.pdf
2. CIPM Recommendation 1 (CI-2005). http://www.bipm.org/cc/CIPM/Allowed/94/CIPM-Recom1CI-2005-EN.pdf
3. The International System of Units (SI). BIPM, 2006, Sèvres, France. http://www.bipm.org/en/si/si_brochure/
4. Preston-Thomas H.: Metrologia 27, 2 (1990)
5. The Provisional Low Temperature Scale from 0.9 mK to 1 K, PLTS-2000. Appendix to Recommendation C1 (CIPM, 2000). http://www.bipm.org/utils/en/pdf/PLTS-2000.pdf