bibtex-autokey-titleword-abbrevs

bibtex-autokey-titleword-abbrevs is a variable defined in `bibtex.el'.
Its value is

nil

Documentation:
Determines exceptions to the usual abbreviation mechanism.
An alist of (OLD-REGEXP . NEW-STRING) pairs. Case is ignored
in matching against OLD-REGEXP, and the first matching pair is used.
See `bibtex-generate-autokey' for details.

You can customize this variable.