Excel VBA to Export Selected Sheets to PDF

I'm using the following code to export selected sheets from Excel 2010 to a single pdf file...

ThisWorkbook.Sheets(Array("Sheet1", "Sheet2", "Sheet3")).Select

ActiveSheet.ExportAsFixedFormat _
        Type:=xlTypePDF, _
        Filename:="C:\temp.pdf", _
        Quality:=xlQualityStandard, _
        IncludeDocProperties:=True, _
        IgnorePrintAreas:=False, _
        OpenAfterPublish:=True

My problem is that it only exports the first sheet. Any ideas?