Using the Sources tab
What are recent sources?
The 50 sources that you used most recently appear in your recent sources list on the Power Search form. These sources are indefinitely retained, unless you remove them. To edit your recent sources, click on the Edit This Source List option at the bottom of the Sources drop-down list.
What are favourite sources?
You may identify up to 100 sources as "favourites." Favourite sources are highlighted in blue in your sources list, and they remain there until you choose to remove them. You designate sources as favorites after locating them in the Sources tab. For help with browsing or finding a source, see How do I locate sources using the Sources tab?