Angus Hamilton, Afghanistan, pp. 262-268. New York, 1906.
Sir Thomas Holdich, India, pp. 98-99. London, 1905.
Merzbacher, Aus den Hochregionen des Kaukasus, Vol. I, pp. 55-56, 156. Leipzig, 1901.
W.Z. Ripley, The Races of Europe, pp. 281-283, 289-290, map p. 285. New York, 1899.
Ibid., 282.
Article Tyrol, Encyclopædia Britannica.
Archibald Little, The Far East, 131-132. Oxford, 1905. Isabella Bird Bishop, The Yangtze Valley and Beyond, Vol. II, 132-133, 146-147, 166, 174, 207-210. New York and London, 1900. S. Wells Williams, The Middle Kingdom, Vol. I, p. 43, New York, 1904. J. Naken, Die Provinz Kwangtung und ihre Bevölkerung, Petermanns Geographische Mittheilungen, Vol. 24, p. 421. 1878.
Archibald Little, The Far East, pp. 307-308. Oxford, 1905.
E.C. Semple, The Anglo-Saxons of the Kentucky Mountains, Geographical Journal, Vol. XVII, pp. 588-623. London, 1901.
Sir Thomas Holdich, The Origin of the Kafir of the Hindu Kush, Geographical Journal, Vol. VII, p. 42. London, 1896.