Internet History Sourcebooks Project
Fordham University: Modern History Sourcebook: Sir Walter Raleigh/guiana
Fordham University offers Sir Walter Raleigh's text entitled "The Discovery of Guiana." It is very specific and descriptive.
Luminarium
Luminarium: Sir Thomas More
This comprehensive site offers biographical information concerning Sir Thomas More, texts of his works, articles and essays about his works, and a list of other available sources.
Other
Apostles.com: Thomas More's Last Letter
Text of Thomas More's last letter written to his daughter Margaret on the day before he was executed. Cited from "St. Thomas More: Selected Letters" by Elizabeth Frances Rogers.