I seem to keep about 10 or 12 at a time, depending on how many I've read since the last time I hunted up more content, of course. Plus I have a variant of the Bible that I've split up into 38 (or 39, I can't remember off-hand) "weekly reading" chunks, according to a plan our Education Minister came up with from somewhere. Plus a full version of the Bible that was posted here on MR (that has book/chapter/verse links in it). So what? About 50 individual 'book' files altogether. And, oh, yes, they
are in collections!