==External links==*Australian Contract Law*Uniform Commercial Code "(United States Contract Law)"*Cornell Law School "contracts: an overview"*Principles of European Contract Law*United Nations Convention on Contracts for the International Sale of Goods, Vienna, 11 April 1980*LexisNexis Capsule Summary: Contracts
Atiyah, "The Rise and Fall of Freedom of Contract" (1979) Clarendon Press ISBN 0-19-825342-7*Randy E. Barnett, "Contracts" (2003) Aspen Publishers ISBN 0-7355-6535-2*Scott Fruehwald, "Reciprocal Altruism as the Basis for Contract," 47 University of Louisville Law Review 489 (2009).