There is no simple answer to this question, because our e-book collections vary greatly. Some only permit reading the e-book online in a web browser. Some permit downloading individual chapters of an e-book as PDF files, but the entire e-book is not available as a single file.

ProQuest Ebook Central is one provider that does enable downloading of entire e-books in the Epub format, which many e-readers can use. However, the rights to do this are set by the book's publisher, not ProQuest, and there is no definitive list of which titles are available this way. Also, be aware that e-book downloads are similar to checking out a physical book. Some are available for seven days, some for fourteen days. After the "checkout period" your access expires; no titles can permanently reside on your computer or e-reader.