A cell from another workbook (i.e. another file) that is referenced in this workbook.
Filename being referenced.
Relevant defined names from an external workbook.
Relevant worksheets from an external workbook.
These will only be a subset of sheets needed to run calculations, so indexes from the original workbooks will not be preserved.
A cell from another workbook (i.e. another file) that is referenced in this workbook.