There is ongoing research, at least I found this interesting doctorate's degree paper (uh, words?) from Norway.
https://www.duo.uio.no/handle/10852/12729
You can dl the whole paper from that page if you want to. If it does not work, for some reason, just PM me, I have a copy. It is in the public domain (at least in Scandinavia) so don't worry about copyright.