Harper, M R; Smith, A J A; Basu, A; Humphreys, D A (2004) Calibration of a 70 GHz oscilloscope. In: Conference on Precision Electromagnetic Measurements (CPEM) 2004, 27 June - 2 July 2004, London, UK.
Smith, A J A; Harper, M R; Basu, A (2003) Progress in high-speed time domain metrology at NPL. In: 62nd ARFTG Microwave Measurement Conference, 4-5 December 2003, Boulder, USA.