12. The computer-readable medium of claim 11 , wherein the citation scores of the web page for other books referenced on the web page are each at least a predetermined percentage less than the citation score for the particular book.
12. The computer-readable medium of claim 11 , wherein the citation scores of the web page for other books referenced on the web page are each at least a predetermined percentage less than the citation score for the particular book. 13. The computer-readable medium of claim 12 , wherein the particular book and each of the other books are described by respective book metadata.