Johnson, T., & Hunter, R. (2017). Changes in homeland security activities since 9/11: An examination of state and local law enforcement agencies’ practices. The Journal of Police Practice & Research, 18(2), 160–173.
Davis, P. (2020). Terrorists, spies, and cyber criminals: The FBI on threats to the homeland. Journal of Counterterrorism & Homeland Security International, 25(2), 12–16.