Five alternative ways to close documents are:
Choose File > Close Document to close all of the windows associated with the document in the active window.
Choose File > Close Window to close the active document window.
Choose File > Close All to close all of the windows associated with all of the open documents.
Click the title bar close button of any document window to close it.
Choose iStudio Publisher > Quit iStudio Publisher to close the application and in so doing close all of the document windows.
NOTE: In all of the above cases, if the closure will result in the complete closure of one or more documents with unsaved changes then for each unsaved document a warning message is displayed and you are given an opportunity to save it.