I have been looking for a menu item that allows me to move an item from one subcollection to another for organization. Example if I find that I have a acquired a lot of references on a particular topic but are spread out over several subcollections and I want to move them all to one subcollection. The only method I have found is to drag and drop the item into the destination subcollection, which copies it there, and then go back and delete the original item in the original subcollection. I understand the reason for this and it is a useful function but to just move the item it is a cumbersome procedure especially if there are dozens of articles to be moved.