When you have no further use for an item, you can delete it from your research folder.
To delete an item from a research folder
In the left pane, click the folder from which you want to delete some items.
In the Review pane, select one or more items that you want to delete.
To select multiple adjacent items, hold down the Shift key and click the first and last item in the range. To select multiple, nonadjacent items, hold down the Ctrl key and click the required items.
Choose whether to delete the selected items only or all the items in the folder.
More Information