John Nash — the Princeton game theorist who shared the 1994 Nobel Prize in economics and was portrayed by Russell Crowe in A Beautiful Mind — died in a car crash on May 23, along with his wife, Alicia. In light of his passing, Princeton has digitized his academic file and released it to the public; you can see the full PDF here.
Probably the best document it contains is a recommendation letter by Richard Duffin, Nash's undergraduate advisor at the Carnegie Institute of Technology (now Carnegie Mellon), to Solomon Lefschetz, a math professor at Princeton, where Nash was applying to grad school:
The letter was successful. Nash went on to get his PhD at Princeton. His dissertation, "Non-cooperative games," introduced a concept that would become known as the "Nash equilibrium," a crucial concept in game theory. Khan Academy explains the idea, and how it relates to the famous prisoner's dilemma game, here:
Nash's dissertation has been cited about 7,189 times, according to Google Scholar, though that excludes many uses of the term "Nash equilibrium" that don't cite the actual paper. "If Nash got a dollar for every time someone wrote or said 'Nash equilibrium,'" Princeton economist Avinash Dixit once wrote, "he would be a rich man."
Nash submitted his thesis in May 1950, when he was 21 years old. It was a mere 27 pages long, which includes an acknowledgements section and a very short bibliography. The entire dissertation cites only two sources: game theory's founders John von Neumann and Oskar Morgenstern, and John Nash.