Looking for references on Centripetal (Centrifugal) habitation wheels.

[Boothby171]

I'll be giving a presentation in March, 2004 for the ASCE "Earth and Space" conference, on methods of transit between fixed and centripetally rotating sections of (far future) spaceships and space stations.

I'm looking for pointers to current thoughts & papers on rotating human habitats in space, so I can make sure I'm not duplicating existing concepts (that would be embarassing!)

Thanks in advance.

--Steve