Literature: The Anna-Lisa and Sven-Erik Beckeman "1878/83 Large Dragons", Sotheby's / Corinphila sales 1-3 complete from 1996/97, and "1885 Small Dragons, 1894 Dowager Empress, 1897 New Currency Surcharges, 1897 Red Revnues & Customs Mail Handstamps", sales 1-4 complete. Fresh and very fine sets, an invaluable reference work. (Image 1) (Image 2) (Image 3) (Image 4) (Image 5) (Image 6) (Image 7) (Image)