Re: Storage of Specialization Buildings

Tap and Hold the item ... a Blue 'storage box' will appear top right underneath the 'bulldoze' icon.  Then tap on the storage box to move the item [you get a Cancel/Store It! option].  To get it back, go to the Specialisation category, and you'll see the Blue box showing against the icon for the stored item ... tap an place as usual.

I'm using it quite a lot already, as I have no spare territory remaining ...  and can't expand as I'm not getting any drop items!