Referencing Cells or Ranges on Other Worksheets
When you work in situations where data that spans more than one sheet in an Excel workbook must be summarized, you need to include cell references in a formula or function that consist of cell addresses or ranges that are not on the current worksheet (the worksheet that contains the formula or function). For example, you might have created a different worksheet for each quarter of the year that details your sales figures or expenditures, and you want to have a worksheet in the workbook that provides summary information for all four quarters.
The syntax for a cell reference on a worksheet that is in the same workbook as the sheet you are working on is
'sheet name'!cell address. The single quotation ...