Jean,
The report by the Union of Concerned Scientists titled, "A New Road" has a lot of good information in it. It's a little dated at this point, but it is, I believe, the study that coined a lot of the terminology that's being bantered about, mild hybrid, full hybrid, etc. I could be wrong there, though.

It's not exactly what you're looking for, but it may help. You can download a .pdf copy at http://www.hybridcenter.org/hybrid-c...ad-report.html