"BookLamp.org is a system for matching readers to books through an analysis of writing styles, similar to the way that Pandora.com matches music lovers to new music. Do you like Stephen King’s It, but thought it was too long? The technology behind BookLamp allows you to find books that are written with a similar tone, tense, perspective, action level, description level, and dialog level, while at the same time allowing you to specify details like... half the length. It’s impervious to outside influences - like advertising - that impact socially driven recommendation systems, and isn’t reliant on a large user base to work."
M. Koch, M. Lacher, and W. Wörndl. Proc. WETICE-2001 - Workshop on Web-based Infrastructures and Coordination Architectures for Collaborative Enterprises, (June 2001)
S. Stober, and A. Nürnberger. Knowledge-Based Intelligent Information and Engineering Systems (KES 2006), volume 4251 of LNAI, page 763--770. Berlin / Heidelberg, Springer Verlag, (October 2006)