What non-Perl books do you recommend to Perlers?
I'm overhauling the perlbook documentation and moving the book list from perlfaq2 into it. Besides updating the references, I'd like to include a short section on non-Perl (technical) books that are useful to the Perl programmer. So far I have Jon Bentley's Programming Pearls, but that's an easy one.
What else is there? What other books do you think Perlers should read to help them be better Perl programmers?
Just to head off all the posts I know are coming, Lord of the Rings might help you understand the perl source code, but it's not going in perlbook.
Okay, maybe it is.