At Princeton, von Neumann lectured in the nascent field of quantum theory and through his work on rings of operators (later renamed Neumann algebras) he helped develop the mathematical foundations of that theory which were unveiled in the paper "Mathematische Grundlagen der Quantenmechanik" (1932). His seminal publication on game theory, "Theory of Games and Economic Behaviour" was published in 1934 with co-author Oskar Morgenstern.