Additional paper [8] (useful reference; not required)
Friedman, A. S. \& Bloom, J.S. 2005, ApJ, 627, 1 Discusses the application of the Ghirlanda rtelation for inferring the cosmological parameters, does a careful job, stresses the uncertainties the problems that must be dealt with, and urges for caution.
The link address is: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2005ApJ...627....1F&db_key=AST&data_type=HTML&format=&high=44eb79798431893