I found some pages about TWO-MIX written in English.
New links are Welcome. Please let me know.
Beginner's Gate by Yuh-iro
the TWO-MIX electronic library by Kaijyuu Miyuki-chan.
This page is in Kaijyuu_m's web-space directory.
TWO-MIX Little Planet
You can also see Chinese version from Opening page.