Looking for articles on E30's and Z4 LSD

A colleague of mine is looking for two things:

1. Original articles on E30's (I know there's a site with several articles, but can't remember the URL), especially those in which the vehicles were actually weighed, not the BMW published figures
2. Retrofit LSD components for non LSD cars (especially Z3/Z4)

Who can help?

1. Original articles on E30's (I know there's a site with several articles...) - e30world.com

Thanks for your reply, but I meant magazine articles in which they actually weighed the vehicle.

318is review: [webgraphx.com]

as for Z4 diffs, I'm sure Quaife makes an LSD for the Z4.