the ones I have sampled thus far fail in categories 1, 2, and 4. As well as being rather hit-or-miss in terms of quality and/or relevance. As well as not being BOOKS. They are thus mere fragments, and require either a lot of printing OR switching back and forth from window to window - which I find tedious, annoying, and distracting from the lesson plan. I am very old-fashioned, and prefer reading detailed data in hardcopy to doing so on-screen. Thanks, though. But my question stands as stated.