Craig Timberg et al., “Russian Ads, Now Publicly Released, Show Sophistication of Influence Campaign,” Washington Post, Nov. 1, 2017.

Jack Nicas, “How YouTube Drives People to the Internet’s Darkest Corners,” Wall Street Journal, Feb. 7, 2018; Paul Lewis, “ ‘Fiction Is Outperforming Reality’: How YouTube’s Algorithm Dis-torts Truth,” Guardian, Feb. 2, 2018; Jon Swaine, “Twitter Admits Far More Russian Bots Posted on Election Than It Had Disclosed,” Guardian, Jan. 19, 2018; Philip N. Howard et al., “Social Media, News, and Political Information During the US Election: Was Polarizing Content Concentrated in Swing States?” Computational Propaganda Research Project, Sept. 28, 2017.