Remove reference to external workbook

I have a workbook that used to refer to an external workbook (separate file) but the data was transferred to an internal sheet and the ranges redefined however whenever the workbook is loaded I get a message saying that automatic updates of external links have been disabled and when I click on the Allow updating button, I get a message saying that the external file could not be found (true, it’s not there).
Where should I look for the reference to delete it since it doesn’t appear in any formulae and there are no macros recorded under “My Macros & Dialogs”?
Thanks, Cheers, Greg

Choose Edit - Links to External Files.- Break Link

Thank you JohnSUN! I have copied your comment to the answer but don’t know how to give credit to you in the sustem?

from JohnSUN’s comment:
Choose Edit - Links to External Files.- Break Link
JohnSUN gravatar imageJohnSUN ( 42 hours ago )