1) H. Preston-Thomas: The International Temperature Scale of 1990 (ITS-90), Metrologia, 27, 3/10 (1990)
2) H. Preston-Thomas: T.J. Quinn, Supplementary Information for the International Temperature Scale of 1990, p 44, Bureau International de Poids et Mesures (1990)
3) P. Marcarino and R. Dematteis: A. Tiziani, Calibration of SPRTs at the ITS-90 freezing points, Proc. XIII IMEKO World Congress, 1377/1382 (1994)