online de Medina, Pedro (1548) Libro de las grandezas y cosas memorables de España. Seville. (1595 edition, Alcala de Henares: Iuan Gracian, online Morison, S.E. (1940) Portuguese voyages to America in the fifteenth century Cambridge, Mass: Harvard University Press. Morison, S.E. (1955) "Review of Cortesão's 'Nautical Chart of 1424'", Speculum, Vol. 30 (3), p. 467-70. Nansen, Fridtjof (1911) In Northern Mists; Arctic exploration in early times. New York: F.A. Stokes. vol. 1, vol. 2 Nordenskiöld, Adolf Erik (1897) Periplus: An Essay on the Early History of Charts and Sailing Directions, tr. Frances A. Bather, Stockholm: Norstedt. O'Curry, Eugene (1861) Lectures on the Manuscript Materials of Ancient Irish History, delivered at the Catholic University of Ireland, during the sessions of 1855 and 1856. Dublin: Duffy. p.289). La Ronciere, Charles de (1924) La carte de Cristophe Colomb, Paris: Champion Spence, Lewis (1925) The Problem of Atlantis. London: Rider. Vignaud, H. (1902) Toscanelli and Columbus: The letter and chart of Toscanelli on the route to the Indies by way of the west, sent in 1474 to the Portuguese, Ferman Martins, and later on to Christopher Columbus; a critical study on the authenticity and value of these documents and the sources of the cosmographical ideas of Columbus, followed by the various texts of the letter. London: Sands. online Vignaud, H. (June, 1902) "Did Columbus Discover America?", Everybody's Magazine, June, 1902, Vol. 6, No.6, p.549. Atlantis Phantom islands of the Atlantic Mythological islands Pre-Columbian trans-oceanic contact