[plt-scheme] Reference for PLT-Scheme for paper

Hi all,

I am preparing a paper for ICFEM'09 regarding the implementation of an
explicit model checker for Event-B completely written in PLT Scheme.
What's the best reference for PLT-Scheme? It seems that the first
occurence of PLT-Scheme / DrScheme is:
http://dblp.uni-trier.de/rec/bibtex/conf/plilp/FindlerFFKF97

but I am not so sure that this is the current best reference for the
PLT Scheme project.
Any suggestions?

Cheers,

-- 
Paulo Jorge Matos - pocmatos at gmail.com
http://www.pmatos.net