Is there a service/app/site that offers recommendations on other books based on the citations that are found in a book you liked?I've started noticing that the books I have read and liked tend to mention authors of other books that I've read and liked. Tversky and Kahnemann come up in a lot of books as an example, I like to read non-fiction mostly. So that lead to new books by the two authors that I've enjoyed.That got me thinking that you can possibly apply a type of pageRank algorithm to citations or toss the connections in a graph database and see the number of relationships between books (popularity based on citations) and work your way backwards from the books you liked to new books that are connected.Wondering if you've ever come across something like that that you can recommend?