Brian Clark, “The Three Key Elements of Irresistible Email Subject Lines,” Copyblogger, August 26, 2010, доступно на
138
Melissa Korn, “Tweets, Plays Well w/Others: A Perfect M. B.A. Candidate,” Wall Street Journal, September 1, 2011; Ian Wylie, “Learning the Game of Social Media,” Financial Times, September 5, 2011.