Good quality math ebook source? Can anyone recommend a good source of technical ebooks?   Amazon (Kindle) is out IMHO since many of their graduate level and above math and physics books have grossly inadequate renderings of the equations. (Sadly I already own several of these.) Google math books are formatted far better than Kindle (although a more limited number of offerings) but seem to be restricted to online use, which is also a deal breaker for me.   Anyone know of Google quality math book formatting in a downloadable and ebook-readable format?  (I have tried Adobe Digital Editor on downloaded Google books some time ago but found the paging to be too erratic.)  
 A: Readable e-books with good rendering of mathematical equations and symbols include those in the PDF and DjVu file formats. Sometimes the e-books with equations, indices, symbols and mathematical content are more readable in PDF format, but the files in PDF are usually bigger than the same files or documents in DjVu.
According to my experience, scientific or mathemtical e-books with few equations can be viewed or rendered well in the epub file format.
A website with free technical or mathemtical e-books, many of them from past years or decades or of historical significance and in the PDF and DjVu formats, is the internet archive site.
This site has math and science e-books that can be purchased, mostly in the PDF and epub formats.
The ebooks directory site has links to many free math books online.
This website has many e-books and textbooks related to engineering and mathematics in PDF format.
Here Free math ebooks can be downloaded in PDF format.
One can search directly for readable math lecture notes or courses with a search engine such as Google by typing for example "topology notes pdf",  "topology course pdf", "[math topic] lecture notes pdf", and similar sentences.
