J. Nash, "The Bargaining Problem", 1950, Econometrica.

http://www.people.cs.uchicago.edu/~codenott/NashBargaining.pdf

J. Nash, "Two-Person Cooperative Games", 1953, Econometrica.

http://www.people.cs.uchicago.edu/~codenott/NashCoopGames.pdf