To download reference material from the Document list, follow these steps:
Open the desired project from the Projects list.
Check the box next to the document you want to download reference material from.
In the Actions menu; type and select Download Reference Material.
A zip file with all Reference Material will download automatically.
If one file is selected, the zip file will have the same name as that file. If more than one file is selected, it will have the name of the project.
To learn how to download Reference Materials from the Workbench or Task List see here.