Hello
I have found this reference in this group:
AS SOON AS YOU FINISH MAKING CHANGES, UNGROUP YOUR SHEETS. Otherwise you
will commit a common mistake - Thinking you are changing one sheet when
you'rea ctually changing them all.
I have already committed this mistake: deleted several unneeded rows in
worksheet 2 and the rows, much needed, disappeared from all other
several worksheet. Thankfully I only edited worksheet 1 by that
moment...
I'll need to use the spreadsheet I had before editing, but it still has
3-D reference.

How to UNGROUP worksheets, please? I cannot find an answer to this
question in Excel's Help.

Thank you
Galina