Oh boy .... endless but I do have a couple old standbys I use.
And your old standby is also an excellent choice, I try to shy away from price guides anymore, the market is so volatile. I have many, many of Stanley Blocks old hardback books, they are truly the best all arounds I have ever found. I used to call Stan all the time years ago w/ marble related questions, he loved it, always willing to share, I'm not so sure his other half shared the sentiment.