Knyphausen, K., Münz- und Medaillen Kabinet des Grafen Karl zu Inn- and Knyphausen, Hannover, 1872, x + 419pp, 2 plates; Knyphausen, K., Erster Nachtrag zum Münz- und Medaillen Kabinet des Grafen Karl zu Inn- and Knyphausen, Hannover, 1877, iv + 232pp, 6 engraved plates; Rosenberg, Sally, Münz u. Medaillen-Kabinet des Freiherrn Wilhelm Knigge, Hannover, 1901, v + 323pp; Prober, K., Historia Numismatica de Guatemala, Sao Paulo, 1954, 184pp including plates, copy no. 145, signed by the author; Spassky, I.G., The Russian Monetary System, Amsterdam, 1967, 253pp, illustrations in text; together with other references (10), by Sabater, Calbeto, Crusafont, Mira, Droulers, etc [15]. First two in modern cloth, third in maroon half-leather, others in publishers’ bindings [weight 20 kg] £70-90