1. 1.8 K test of binary and ternary superconducting conductors
2. Lake Shore Cryotronics Inc. Model CGR-1-2000, Serial C1201. This resistor has been checked against vapour thermometers periodically, as well as against other secondary standards as part of the thermometry used in the Energy/Saver Accelerator at Fermilab
3. Mitshuishi Electric Company
4. Smathers, D, Larbalestier, D. Private Communication