1. Clark “Productivity Growth without Technical Change.”
2. Gregory Clark, “Productivity Growth without Technical Change: European Agriculture before 1850” (unpublished manuscript). See also Gregory Clark, “The Cost of Capital and Medieval Agricultural Technique” (unpublished manuscript).
3. Clark, Cotton Goods in Latin America, Part I, p. 22.
4. Clark, Cotton Goods in Latin America, Part II, p. 48.