ProQuest's eBook Central has two different ways you can read their titles:
Offline checkout (download):
Sign in to your free eBook Central account.
Find the book you want to download, and click "Download Book".
Choose the device on which you are attempting to access the eBook (Laptop/Desktop, iOS device, Android device, other).
Either download Adobe Digital Editions or confirm that you already have Adobe Digital Editions.
If prompted, choose a download format from the options provided, and click “Download”.