Keeping track of and managing all your import sources is easy. Click the 'Manage sources' button in the top left corner of the 'Discover' feed of "All channels".

If you want to manage sources for a specific channel, access that channel via the navigation bar on the left hand side and select 'Manage sources' in the 'Discover' tab.

The window shows the names of your sources, the type of import source, the total number of content updates shown in the 'Discover' feed, and if they are currently active ('Status'). You will also be able to delete the content source by clicking the bin button or edit its details by clicking the gear button.