The Zombie Stack Exchanges That Just Won't Die
I know that link.springer.com offer ebooks downloadable to subscribers.
Do American Mathematical Society and Academic Press have ebooks for subscribers?
Thanks!
Tim
Short answer: Yes, but maybe, No, depending on what you really need.
They have their Contemporary Mathematics and various conference proceedings series available in an PDF format. This is divided into a separate backfile (1980-2011) and a frontfile eBook collections (2012, 2013) see: http://www.ams.org/publications/ebooks/ebooks
AMS has a sampling of electronic books accessible as individual PDFs: see their history of mathematics section at:
http://www.ams.org/samplings/math-history/math-history
These are freely accessible.
As always, evaluation is probably going to be specific to your institution, so do go for a trial and share your experience widely.