Article: For Iceland, see D. Friedman, "Private Creation and Enforcement of Law -- A Historical Case." Journal of Legal Studies, (March 1979), pp. 399-415.

For Homeric Greece, see Posner, R. 1981. The Economics of Justice . Cambridge, MA: Harvard University Press., 119-227.

For Papua New Guinea, see Robert Cooter, "Inventing Market Property: The Land Courts of Papua New Guinea," 25 Law and Society Review 759 (1991).

The norms of Shasta Country are discussed in Chapter 17 of this book and, at greater detail, in D. Friedman, "Less Law than Meets the Eye,"The Michigan Law Review vol. 90 no. 6, (May 1992) pp.1444-1452. and in Robert Ellickson, Order Without Law, the book that the article is a review of.

See also Robert C. Ellickson, A Hypothesis of Wealth Maximizing Norms: Evidence from the Whaling Industry, 5 J.L. Econ & Org. 83, 84 (1989)

Readers interested in a much more extensive discussion of norms may want to look at Eric Posner's new book, Law and Social Norms.