Displays sheets that were previously hidden with the Hide Sheets command. Select one sheet only to call the command. The current sheet is always selected. If a sheet other than the current sheet is selected, you can deselect it by pressing Ctrl while clicking the corresponding sheet tab at the bottom of the window.
Choose Sheet - Show Sheet.
Displays a list of all hidden sheets in your spreadsheet document. To show a certain sheet, click the corresponding entry on the list and confirm with OK.