Kibble, B P; Williams, J M; Henderson, L C A; Atreed, D*; Bramley, P*; Cook, J*; Crisp, P*; Cronin, L*; Knight, B*; Outram, S*; Skinner, D*; Williams, B* (1999) A guide to measuring resistance and impedance below 1 MHz. Technical Report. Institute of Measurement and Control / National Physical Laboratory.