You can find it. You can find it free at http://www.ebookee.com/How-to-Solve-It-Modern-Heuristics_155097.html as a DjVu file. Ebookee has a 30 second wait before your download begins; this is to incite you to pay for a premium service.

I'm way behind on the state of ebooks; I'm off to DjVu.org to investigate djvu readers.

Be well,
rir