“…In addition, Sierpiński graphs were studied from numerous other points of view, recent investigations include [11,16,17,20,23,28,29,30]. We also point out that earlier than the Sierpiński graphs, the so-called WK-recursive networks were introduced in [6], see also [10]. WK-recursive networks are very similar to Sierpiński graphs-they can be obtained from Sierpiński graphs by adding a link (an open edge) to each of its extreme vertices.…”