German article in Die Gartenlaube, 1870, no. 37

German article in Die Gartenlaube, 1877, no. 37

German article in Die Gartenlaube, 1887, no. 12

German article in Die Gartenlaube, 1873, no. 14

German article in Die Gartenlaube, 1877, no. 35

German article in Die Gartenlaube, 1870, no. 34, 37, 39, 41, 42, 47

German article in Die Gartenlaube, 1870, no. 52

German article in Die Gartenlaube, 1878, no. 1

German article in Die Gartenlaube, 1870, no. 42

German article in Die Gartenlaube, 1870, no. 39

painting by Wilhelm Camphausen, formerly Wallraf-Richartz-Museum, Köln