1. Low-velocity impact to transmission line conductors;Waters;Int J Impact Eng,2017
2. Sniper attack on California power grid may have been 'an insider,' DHS says;Pagliery,2015
3. ABB launches substation physical security and resiliency initiative,2015
4. Paul W. Parformak., Physical security of the U.S. power grid: high voltage transformer substations. Congressional Research Service. 2014. Print.
5. Lars Jonsson and Rutger Johannson, High Voltage Bushings 100 years of technical advancement. ABB Review, 2009.