Formula Refers to Sheet not in Workbook!...HELP!

Hi All,

Have been sent a spreadsheet; one which comes from another source other than the person who sent me it i.e. a Third Party.

It has a formula in the spreadsheet which (if i'm right) should be referring to a sheet within my workbook? HOWEVER, There is no sheet (as far as I can see) by that name...!

I have checked:

• Right Clicked on Sheets, to Unhide Hidden Sheets; Option is Greyed out (I assume none hidden then)
• No Macros in Spreadsheet which are hiding or blocking me from getting to anything
• Workbook and/or sheets are not protected
• No Named Ranges in Name Manager

So I am completley stumped! The formula I see is as follows:

=IF(calc_8!$B$534=calc_8!$B$535,calc_8!D3,"")

Anyone here able to help me? I have attached the spreadsheet for you too...I am initially talking about the 8 Fold Tab and the formula I have pasted above is taken from cell D16 on that sheet!

Thanks in advance for your help!