Free Lunar References

There are many resources available on the web, naturally. Here are two, one I have printed and use from time to time; the other has been bookmarked and recently re-discovered. They are both large but can be downloaded in pieces. Check out their respective web pages for more info and see if they're for you.

1. Alan Chu's Photographic Moon Book
2. Don Wilhelms' Geologic History of the Moon (originally published as the United States Geological Survey Professional Paper 1348)