Help edit this code so that it loops through specific worksheets

Hi everyone, can anyone help edit this code so that it loops through specific named worksheets "A", "B", "C","D" in my workbook.

Thanks.

Sub ClearERRvalues()
Dim rng As Range
Dim cell As Range
Set rng = Range("A1:z1000")
For Each cell In rng
If cell.Text = "#DIV/0!" Then
cell.ClearContents
ElseIf cell.Text = "#N/A" Then
cell.ClearContents
End If
Next cell
End Sub