Ken Stone no longer maintains the Catgirl Synth (CGS - Ken Stone's Modular Synthesizer) web site. The following resources will help you if you need to refer to any of the material.
Archival version of Catgirl Synth web site.
CGS projects on Elby Designs.
Catgirl Synth on Synth DIY wiki.
Last archived version on archive.org
(Generic CGS Search on archive.org. No valid pages after Aug 2018)