Erika x Trude doujinshi, 20 pages. Contained a little extra 4 page Yoshika / Lynette insert, printed on rather low quality paper. The scans turned even worse by the fact that this little booklet-thing was in very poor condition. (This is what happens when you buy used doujinshi.)
ED: http://www.mediafire.com/?zz2z80ipte5vr32