↑ Casson, Herbert N., The History of the Telephone, public domain copy at manybooks.net: '"At last," said the delighted manager [J. J. Carty, Boston, Mass.], "we have a perfectly quiet line."'
↑ Jensen Transformers. Bill Whitlock, 2005. Understanding, Finding, & Eliminating Ground Loops In Audio & Video Systems. Retrieved February 18, 2010.
↑ Swallow D 2011, Live Audio, The Art of Mixing, Chap 4. Power and Electricity, pp. 35-39
↑ IEEE Std 1100-1992, IEEE Recommended Practice for Powering and Grounding Sensitive Electronic Equipment, Chapter 2: Definitions
↑ Beltz, R. ; Cutler-Hammer, Atlanta, GA, USA ; Peacock, I. ; Vilcheck, W. (2000). "Application Considerations for High Resistance Ground Retrofits in Pulp and Paper Mills." Pulp and Paper Industry Technical Conference, 2000.
