You could try one or all of these (same authors):

**Dan Edidin and William Graham:** 
  
*Algebraic cycles and completions of equivariant K-theory*
[here][1]

*Riemann-Roch for equivariant Chow groups*
[here][2]

*Equivariant intersection theory*
[here][3]


  [1]: http://projecteuclid.org/DPubS?service=UI&version=1.0&verb=Display&handle=euclid.dmj/1218811402
  [2]: http://projecteuclid.org/DPubS?service=UI&version=1.0&verb=Display&handle=euclid.dmj/1092749343
  [3]: http://www.springerlink.com/content/0txg8xuq8ydqh7uj/