http://www.dlsite.com/maniax/work/=/product_id/RJ069437.html
this one is pretty rare
found one torrent through searching and downloaded it, but it seems like the files are corrupted after many attempts to get it running.
http://www.dlsite.com/maniax/work/=/product_id/RJ082582.html
http://crocore.sakura.ne.jp/1a2/index.html
lots of links exist but they all have password protection on the zip folders