The chapter that was included in Range Murata’s artbook, 138E. It’s a pretty nice artbook, I recommend it for any buyfags (has giant loli posters drawn by Range and co.).
It came with a DVD as well, which contained a short animation to accompany the chapter. The ISO is up, if anyone wants to produce a superior encode (anti-aliasing, etc.).
If you’re interested in interviews, there’s one translated on Mangabrog’s site (and other interesting interviews).