Try searching for Robert Heinlein books on Kindle for example. You’ll find only six. But don’t rush to trade your Kindle in for Nook, Sony eReader or even iPad – you will find exactly the same selection there – I’ve checked. However if you head over to pretty much any torrent tracker you will find full Heinlein bibliography floating around in zipped PDF files. So while publishers cling to their old business models or argue who is going to charge whom and how much, books are being pirated because there is absolutely no way to get these and other works of literature in digital form. Hopefully it will get better just as it did with music industry.