Nobel Media AB
The Nobel Prize: The Nobel Prize in Literature 1950
This website from the Nobel e-Museum provides information on the 1950 recipient of the Nobel Prize in Literature, Earl (Bertrand Arthur William) Russell (1872-1970 CE), an author who was honored for his "varied and significant writings...
Wikimedia
Wikipedia: Isaac Newton
In the Spanish langauge, discover the life and works of Isaac Newton. This site highlights his work and also provides links to obtain a greater understanding of these individual works.
Stanford University
Stanford Encyclopedia of Phil.: Principia Mathematica
This site from the Stanford Encyclopedia of Philosophy briefly explains the history and significance of the famous logical treatise by Whitehead and Russell. Lists the table of contents from each of its three volumes.