Booklet Pane of 4 nos of commemorative postage stamps on the Stockholmia 74, Philatelic Exhibition, Stockholm : Issued by Sweden Issued on Apr 2, 1974 Issued for : Stockholmia 74, philatelic exhibition, Stockholm, held on Sept. 21-29,  Picture : UPU Type of 1924 Colour : 20o – Green, 25o –