monmo bokujou

I am trying to look for モンモー牧場 (Monmo Bokujou) strike witches doujinshi but can't find them. However, most of them are by the author ウーロン・レイ(Uron Rei) All of doujinshi can be preview in this website.... (http://doujinshi.mugimugi.org/browse/author/42656/Uron-Rei/) Note: some of it can be buy...