External workbook references can appear in formulas, defined names, objects, and charts. The Ablebits guide explains why one simple search does not necessarily locate every linked item. A cell search is a useful starting point, but it is only part of the audit.

Look Beyond Cells When Auditing Excel External References

The example searches for .xl to help identify several Excel filename extensions and lets the search scope cover a sheet or the workbook. Review each link's role before breaking it, since removing a connection changes future updates. Check other reference locations when the workbook still depends on an unexpected external source.