Arnold, S.E., 2010. Twitter can lower marketing costs -- how to put the cost effective service to good use, Smart Business San Diego.
Brown, J., Broderick, a.J. And Lee, N., 2007. Word of mouth communication within online communities: conceptualizing the online social network, Journal of Interactive Marketing, 21(3), pp.2-20;
Curran, James M. 2011. Lennon, Ron. Participating in the Conversation: Exploring Usage of Social Media Networking Sites. Academy of Marketing Studies Journal, Vol. 15.
Doganis, Rigas. The Airline Business in the Twenty-First Century. Book by Routledge, 2010.