1. House and Senate. Joint Hearing before the Subcommittee on National Security and the Subcommittee on the Interior. The EMP Threat: The State of Preparedness Against the Threat of an Electromagnetic Pulse (EMP) Event. 2015. Statement of Dr. Peter Vincent Pry. Page 1. Available at
https://republicans-oversight.house.gov/wp-content/uploads/2015/05/Pry-Statement-5-13-EMP.pdf
2. House. Committee on Armed Services House of Representatives, One Hundred Eighth Congress Second Session, 22 July 2004. The Report of the Commission on the Threat to the U.S from Electromagnetic Pulse Attack. Statement of W. Graham. Page 20. Available at
http://commdocs.house.gov/committees/security/has204000.000/has204000_0.HTM
. Accessed 9 May 2019.
3. Parfomak PW (2014) Physical security of the U.S. power grid: high-voltage transformer substations. Congressional Research Service, p 6 Available at
https://fas.org/sgp/crs/homesec/R43604.pdf
4. “ High-impact, low –frequency event risk to the north American bulk power system. A jointly-commissioned summary report of the north American reliability Corporation and the US Department of Energy’s November 2009 workshop.” 2010. Page 88. Available at
https://energy.gov/sites/prod/files/High-Impact%20Low-Frequency%20Event%20Risk%20to%20the%20North%20American%20Bulk%20Power%20System%20-%202010.pdf
5. Cuyahoga Books;DK Goldberg,2011