This guide gives you an overview of recommended sources for philosophy:
The page 'New in the collection' shows recent additions to the philosophy collection of the Erasmus University Library, with an option to subscribe to updates.
Go to BrowZine or download the free app from the App Store or Google Play and log in with your ERNA ID.
For more information, view the BrowZine page.
Below is a list of databases with ebooks for the field of philosophy. If you are looking for a specific title, it's better to use sEURch, because there all publishers are covered.
For teachers: if you are looking for online access to a specific book, please let me know, than I can check the available options.