There are a lot more e-book / e-content resources, some that Yale subscribes to and some that are free to the public. Nested under this tab are several more resources you should explore as you look for digital content on the internet.
ACLS Humanities E-Books
Books 24x7
Internet Archive
Open Library
World Digital Library
Center for Research Library
Projects Gutenberg & Muse
OverDrive
SpringerLink