[texhax] Tweaking BibLaTeX sorting

[Joel C. Salomon]

I’ve got two books in my bibliography by the same author and published
in the same year: “Modern Control Systems” and “Advanced Modern Control
Systems”, and I’d like “Modern” to come before “Advanced Modern” in the
listing.

I tried the no-sorting option in BibLaTeX, but that gave me something like:

Thor, A.U. (1998b) Modern Control Systems etc. etc.
— (1998a) Advanced Modern Control Systems etc. etc.

Notice that the first reference listed is labeled “1998b”—not what I’m
looking for!

I found a bunch of sorting option in the BibLaTeX docs, but I couldn’t
figure this bit out.  I don’t want this to affect the sorting of
anything else in the list.

Thanks,
—Joel Salomon