Good in depth references

I'm looking for something more in depth than the brief info sheets from Kodak and Ilford; something like a textbook. Reading around I've seen mention of Ansel Adams' series, specifically the Negative and the Print, and also Way Beyond Monochrome. Are there any others worth looking into? What's the difference between these two options?

If the introduction material left you hungry for more...

I've been fortunate to have received a hardcopy of this book from Laser.

I have enjoyed it as it is giving me many good ideas.

Not only an excellent reference, but a very good value because it is free...

Mees - Theory of the Photographic Process

is available here

Both the AA series and WBM are excellent references for the practical side of photography. Mees is very out of date. There is Mason which is a bit newer and also Glafkides. The very last text on the technical side is the two volume set by Grant Haist.