By Freedman, Michael. New York Random House 1996 . 194 p. 0679764577
By Oldenburg, Zoe. New York Panteon Books 1966 . 650 p. , Translated from the french by Anne Carter
By Wright, John Kirtland. New York American Geographical Society 1925 . 563 p.
By Strong, C. F.. London University of London Press LTD 1964 . 223 p.
By Erdmann, Carl. Damstadt Wiss. Buchges. 1980 . 420 p. , Donación: Der Deutschen Forschungsgemeienschaft Bonn-Bad Godesberg ; DFG 35340019990
By Heck, Karl. Bad Mergentheim : Kulturverein e. V. Bad Mergentheim, s./f. . 59 p. : , COLECCIÓN GENERAL
By Mayer, Hans Eberhard. Stuttgart Kohlhammer 1980 . 300 p , Donación: DFG 3170057448