Sub t()
     a = ThisWorkbook.LinkSources
     ActiveSheet.[a1].Resize(UBound(a)) = Application.Transpose(a)
End Sub

Sub ListExtLinks()
     Dim ws As Worksheet, urf As Range, r As Range, re As Object, d As Object, m As Object, i&, dk()
      
     Set re = CreateObject("vbscript.regexp")
     re.Pattern = "(?:\[(.+?xls[xmb]?)])([^!']+)": re.Global = True
     Set d = CreateObject("scripting.dictionary")
      
     For Each ws In ThisWorkbook.Worksheets
         Set urf = ws.UsedRange
         If Not urf Is Nothing Then
             For Each r In urf.Cells
                 If r.Formula Like "*xls?]*" Or r.Formula Like "*xls]*" Then
                     Set m = re.Execute(r.Formula)
                     For i = 1 To m.Count: d(m(i - 1).submatches(0) & "|" & m(i - 1).submatches(1)) = 0&: Next
                 End If
             Next
         End If
     Next
      
     If d.Count Then
         dk = d.keys
         For i = 1 To d.Count
             ActiveSheet.Cells(i, 1).Resize(, 2).NumberFormat = "@"
             ActiveSheet.Cells(i, 1) = Split(dk(i - 1), "|")(0)
             ActiveSheet.Cells(i, 2) = Split(dk(i - 1), "|")(1)
         Next
     End If
End Sub