[Lingo] Online reference for Japanese grammar?

["Niels Kobschätzki" <n.kobschaetzki@example.com>]

Hi!

I have to do here some translation work for university and I got stuck
several times because of some rare grammar forms I cannot find in my
grammar references (A dictionary of intermediate Japanese grammar and
A dictionary of basic Japanese grammar).
Are there any *good* online grammar references for Japanese?
(hopefully in English - but in Japanese it should work as well)
Until now I could find only stuff that covers really really basic stuff.

Niels