Beschreibung
van der Molen, P.W., The Origination of the Swaziland King George VI Definitives; Ryan, Gary, A Bird's- Eye View of Revenue Philately, Beiträge in The London Philatelist, June 1998, Nr. 1256 #56802
van der Molen, P.W., The Origination of the Swaziland King George VI Definitives; Ryan, Gary, A Bird's- Eye View of Revenue Philately, Beiträge in The London Philatelist, June 1998, Nr. 1256 #56802