You can create groups and subgroups in your EndNote library to organize your references.
- Click on the Groups tab and then select Create Group to create a group.
- Select the references you want to sort into your new group.
- Drag and drop them onto the group in the left menu.
If you want to sort multiple groups under a heading:
- Click on the Groups tab and then select Create Group Set to create a heading.
- Mark the group set you just created.
- Click on the Group tab and then select Create Group to create a subgroup. Note that it is not possible to sort a reference into a group set.
![Group Set and Group](https://dkou0skpxpnwz.cloudfront.net/accounts/54167/images/Group_Set.png)