*** If bibtex-maintain-sorted-entries is non-nil, inserting new
entries is now done with a faster algorithm. However, inserting
will fail in this case if the buffer contains invalid entries or
isn't in sorted order, so you should finish each entry with C-c C-c
(bibtex-close-entry) after you have inserted or modified it.
The default value of bibtex-maintain-sorted-entries is nil.