Why don't you have a New York Public Library card?
Ebooks are becoming a feature in the classroom. And libraries are a good source. While my local public library system has made it easy to get ebooks (and to search for dead-tree books and to have them sent to my nearby branch), it is somewhat limited. At a recent meeting of the Western New York Physics Teachers Alliance, I learned that I have another resource.
Do you live in New York State?If you live in NYS, you are eligible to get a New York Public Library card. While you may not get to visit an actual branch, you can download from their large ebook collection. The shot below is the beginning from a search for "quantum". Many books are on the graduate student level, so the selection is deep.
The actual process of getting the card will take a few weeks. You first request one on their website and wait a couple of weeks until it arrives in the mail. You then need to send in a picture that proves you reside in NYS (unless you want to drive to Gotham and visit one of their branches). Wait a few days and when you get an email confirming your acceptance, you are set to go. It is free, so why are you waiting?
If you are an iPad user, the Overdrive Media app allows you to access the NYPL and read books on that device.