Matea Gold and Frances Stead Sellers, “After Working for Trump’s Campaign, British Data Firm Eyes New U. S. Government Contracts,” Washington Post, Feb. 17, 2017; Nicholas Confessore and Danny Hakim, “Data Firm Says ‘Secret Sauce’ Aided Trump; Many Scoff,” New York Times, Mar. 6, 2017; Joshua Green and Sasha Issenberg, “Inside the Trump Bunker, with Days to Go,” Bloomberg, Oct. 27, 2016.