P. Vidal de la Blache, Tableau de la Géographie de la France, p. 276. Paris, 1903.
E.A. Freeman, Historical Geography of Europe, Vol. I, p. 450-453. London, 1882.
William Morris Davis, Physical Geography, p. 183. Boston, 1899.
P. Vidal de la Blache, Tableau de la Géographie de la France, p. 260, map p. 261. Paris, 1903.
Indian Census for 1901, Risley and Gait, Vol. I, Part I, pp. 1, 2, Calcutta, 1905.
Hans Helmolt, History of the World, Vol. IV, p. 479. New York, 1902.
Sir Thomas Holdich, India, p. 67, cartogram of Hindu Kush orography. London, 1905.
Ibid., pp. 102-104.
Ibid., p. 26.
J. Partsch, Central Europe, p. 27. London, 1903.