«Cotta (family)» . Encyclopædia Britannica (անգլերեն). Vol. 7 (11th ed.). 1911. էջեր 250–251, page 251. «his youngest son, Johann Friedrich, Freiherr Cotta von Cottendorf (1764–1832).... In 1825 he started steamboats, for the first time, on Lake Constance, and introduced them in the following year on the Rhine.»