
For me, when I research, the blank icon of an out of print book on Amazon is a clue not just that I have found something unlikely to have been overused by others, but something I can mold to my purposes (plus they only cost like $.01!).
One of my rules as a reader is to read one book mentioned in or cited in every book that I read. It not only solves the problem of ‘what to read next’ but it sends you on a journey down the rabbit hole.