VB.net Reference for Pivot class

Hi
In VB.net what do I have to reference to use the Pivot class with code like the following
and can this be used in ASP.net:


    Public Function PivotData(RowField As String, DataField As String, Aggregate As AggregateFunction, ParamArray ColumnFields As String()) As DataTable
        Dim dt As New DataTable()
        Dim Separator As String = "."
      Dim RowList = (From x In _SourceTable.AsEnumerable()New With { _
            Key .Name = x.Field(Of Object)(RowField) _
      }).Distinct()
      Dim ColList = (From x In _SourceTable.AsEnumerable()New With { _
            Key .Name = ColumnFields.[Select](Function(n) x.Field(Of Object)(n)).Aggregate(Function(a, b) a += Separator & b.ToString()) _
      }).Distinct().OrderBy(Function(m) m.Name)

        dt.Columns.Add(RowField)
        For Each col As var In ColList
            dt.Columns.Add(col.Name.ToString())
        Next

        For Each RowName As var In RowList
            Dim row As DataRow = dt.NewRow()
            row(RowField) = RowName.Name.ToString()
            For Each col As var In ColList
                Dim strFilter As String = (RowField & Convert.ToString(" = '")) + RowName.Name + "'"
                Dim strColValues As String() = col.Name.ToString().Split(Separator.ToCharArray(), StringSplitOptions.None)
                For i As Integer = 0 To ColumnFields.Length - 1
                    strFilter += " and " + ColumnFields(i) + " = '" + strColValues(i) + "'"
                Next
                row(col.Name.ToString()) = GetData(strFilter, DataField, Aggregate)
            Next
            dt.Rows.Add(row)
        Next
        Return dt
    End Function