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 0-7355-6525-2*Scott Fruehwald, "Reciprocal Altruism as the Basis for Contract," 47 University of Louisville Law Review 489 (2009).
Zato se v pravu uporablja v teh primerih termin pogojni precedens in določuje pogoje, ki morajo biti izpolnjeni, da se pogodba realizira.