ScienceDirect contains e-books in technology and economics.
The e-books are in PDF format, every chapter is an individual PDF file that you can both read online and download, whichever you prefer.
Create a free personal ScienceDirect-account to save lists of books you're going to use several times!
You might have problems to read and save PDF if you are using Internet Explorer. One way to avoid this is to right click and choose “Save target as..."