A diverse variety of papers and books were chosen for my research strategy. Some gave a solid back-drop to significant events, and others a historical aftermath - each equally valued. Two journals gave an in-depth review of historical manuscripts and argued varied topics. Three books gave a broad picture, important for a full spectrum of events starting from the formation of Portugal all the way through to the English occupation of India some 800 years later. Through these sources, I was confidently able to grasp the scope of Portuguese exploration and it's greater significances on the past and modern world.
Northrup, David. "Vasco da Gama and Africa: An Era of Mutual Discovery, 1497-1800." Journal of World History 9, no. 2 (1998): 189-211. Here, Northrup examines the short-term, but mainly the long-term economic and cultural influence da Gama brought to west, south, and eastern Africa from both the Portuguese, and African peoples perspective. He splits the regions up and examines each one carefully - usually taking a neutral stance in-between opposite historical conclusions. This source was very useful for gaining a greater perspective on Portuguese exploits into Africa. Northrups' specificity and break-up into two regions gave great detail and painted a better picture of relations between the African people and the Portuguese.
Domingues, Franciso Contente. "Vasco da Gama's Voyage: Myths and Realities in Maritime History."Portuguese Studies 19, no. 1 (2003): 1-8. In this article, Domingues outlines some of the myths that surround Vasco da Gama's exploration. Can we be sure of what sort of ship Gama sailed to India in? What happened to Gama between 1488 and 1497? What made Gama eligible to be appointed commander of a fleet in 1497? Was he a navigator or not? And further, was he required to be a navigator in order to assume command of that fleet? Domingues argues that "...pilots were supposed to pilot the ship, and captains to command it...". He questions the evidence that supports Gama commanding and piloting the ship, and uses a variety of historical sources to support his arguments. This source gave good insight into what da Gama's role on his voyages actually was.
Bell, Christopher. Portugal and the Quest for the Indies. New York, NY: Harper & Row, 1974 In this short book, Bell first gives a foreground to what paved the way to da Gama's ultimate discovery of a sea-route to India, then goes on to explain what happened on his first voyage, and what the greater outcome of this voyage was. He examines the Portuguese crown in great detail and shows the inner workings of princes and kings that envisioned great prospect from the African voyages. Albeit an older source, Bell makes regular citation to reliable sources such as journals of men that partook in voyages. The history and detail Bell provides gives great insight into what the Portuguese's prerogatives were during this time in their history.
K. G., Jayne. Vasco da Gama and his Successors: 1460-1580. New York, NY: Barnes & Noble, 1970 A book that covers a wide spectrum of events, starting with early Portuguese exploration and ending with the fall of Portugal as one of the greater empires on the worlds stage. Useful for its integration of figures and events that indirectly correlate with Portuguese exploration (such as what Columbus was doing at the time of da Gama's first voyage), making it easier to form a picture of the time. Also of note; the book starts out with a useful chronological table that outlines Portuguese history and relates it to general history from 1460-1580.
Subrahmanyam, Sanjay. The Career and Legend of Vasco da Gama. New York, NY: Press Syndicate of the University of Cambridge, 1997 One of the more useful texts, helped by its date of creation. Subrahmanyam goes into great detail, and draws on a variety of sources to give an excellent modern view of not only Vasco da Gama's voyages, but...