To create a reference to an Object in an Aggregation, Collection, or Edition, use the Navigator to drag it from there and drop it in the tree shown the Aggregations Editor. In this case, the Object will be moved into the Aggregation. If You press CRTL while draging the Object into the Aggretion, the Object will be copied into the Aggregation. In this case, the original object will stay unchanged and a copy of it will be saved in the Aggregation. You can see which Edition an Item belongs to in the Navigator tree or in the “Part of Edition(s)” field in its metadata application form. Save the changes by using [Crtl+S], the icon in the toolbar or “File > Save” in the menu bar. Otherwise a dialog box will open that reminds you to save changes if you quit the Aggregations Editor.