The Dawn of Navigation, Thomas G. Ford, U. S. Naval Institute Proceedings, Vol. XXXIII., 1-3.
The Dawn of Modern Geography, 2 vols., C. Raymond Beazley, 1904.
Portugal
Prince Henry the Navigator, C. Raymond Beazley, 1895.
Vasco da Gama and his Successors, 1460-1580, K. G. Jayne, 1910.
Rise of Portuguese Power in India, R. S. Whiteway, 1910.
Cambridge Modern History, Vol. I., Ch. I.
History of the Indian Navy, Lieut. C. R. Low, 1877.
Spain
The Discovery of America, John Fiske, 1893.