Justus Perthes, Taschen Atlas, p. 38. Gotha, 1905.
Richmond Mayo-Smith, Emigration and Immigration, p. 24. New York.
Ibid., pp. 79-80, 113-115.
Capt. A.T. Mahan, Influence of Sea Power upon History, pp. 27-28. Boston, 1902.
W.Z. Ripley, Races of Europe, pp. 247, 272-274. New York, 1899.
Cæsar, Bella Gallico, Book III, chap. I.
Hodgkin, Italy and Her Invaders, Vol. I, Part I, pp. 34-43. Oxford, 1892.
Ratzel, History of Mankind, Vol. III, pp. 242, 245, 250, 257. London, 1896-1898.
John Fiske, Discovery of America, Vol. I, pp. 316-317. Boston, 1893.
Elliott Coues, History of the Lewis and Clark Expedition, Vol. I. pp. 193-198, 203-212, 240. New York, 1893.