I was wondering if anyone knows of a good BISAC Subject Headings
source for looking up a recommended BISAC based on ISBN, LCSH, etc.
I've found some pages on oclc.org saying they were starting work on
crosswalks and possibly including them in WorldCat but I haven't seen
any returned in any WorldCat api calls yet. I've also read that ONIX
records often have a BISAC code, is there a good source that might
cover many publishers?

http://www.bisg.org/standards/bisac_subject/index.html

http://www.oclc.org/dewey/updates/numbers/

eby