This is all of his lactation themed doujinshi compiled into one tank, just in case anyone was confused.
Although I could've sworn that kind of release had already happened...
@ulkolv:I was right; he released a compilation doujinshi (as opposed to a manga release, which is ostensibly what this is) of all the lactation stuff before, though I don't think it included the follow-up pages at the end, nor the apparent chronology. Forget the title, though.