http://www.newyorker.com/magazine/2017/03/06/trump-putin-and-the-new-cold-war
"A study led by Philip N. Howard, a specialist in Internet studies at Oxford University, found that, during the second debate of the general election, automated Twitter accounts, known as “bots,” generated four tweets in favor of Trump for every one in favor of Clinton, driving Trump’s messages to the top of trending topics, which mold media priorities. Internet researchers and political operatives believe that a substantial number of these bots were aligned with individuals and organizations supported, and sometimes funded, by the Kremlin."
