Kimberly Marten, “The GRU, Yevgeny Prigozhin, and Russia’s Wagner Group: Malign Russian Actors and Possible U.S. Responses,” Testimony before the U.S. House of Representatives Foreign Affairs Subcommittee on Europe, Eurasia, Energy, and the Environment, Hearing on “Exposing and Demanding Accountability for Kremlin Crimes Abroad,” 7 July 2020.