If all the windows are visible on screen, switch between them by clicking anywhere on a document's window.
If the windows are Maximized (i.e. at full screen size,) then:
•Select the document to display by clicking on its name at the bottom of the Window menu.
•Or, press CMD+# (where '#' is the number between 1 and 9 that corresponds to the document window) to cycle between the open windows.
