Friedrich Hayek:

Hayek had made contact with many at the U. of Chicago in the 1940s, with Hayek's The Road to Serfdom playing a seminal role in transforming how Milton Friedman and others understood how society works. Hayek conducted a number in influential faculty seminars while at the U. of Chicago, and a number of academics worked on research projects sympathetic to some of Hayek's own, such as Aaron Director, who was active in the Chicago School in helping to fund and establish what became the "Law and Society" program in the University of Chicago Law School. Hayek, Frank Knight, Friedman and George Stigler worked together in forming the Mont Pèlerin Society, an international forum for libertarian economists. Hayek and Friedman cooperated in support of the Intercollegiate Society of Individualists, later renamed the Intercollegiate Studies Institute, an American student organisation devoted to libertarian ideas.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". What group did Hayek form with three other people?
Mont Pèlerin Society