I am interested in reading more about the social consensus theory. I looked up online, but found nothing more than the Wikipedia article.
Is there a book, or any kind of reference for this topic?
A good start would be Habermas' Theory of Communicative Action. It is very complex and hard to get into for a beginner and even advanced students without guidance, though. But I think every contempory theory regarding social concensus has to deal with the theoretical framework established and defended by Habermas.
For an introduction, see this Wikipedia entry
Nicholas Rescher (1993), Pluralism, against the demand for consensus.
is really non-trivial and, imho, worth reading.