1. Allouche, A. (1994). Mamluk economics: A study and translation of Al-Maqrizi’sIghatah. Salt Lake City: University of Utah Press, specially the chapter, “currency”.
2. Barrow, J. D. (1991). Theories of everything, the quest for ultimate explanation. Oxford: Oxford University Press.
3. Bhaskar, R. (1978). The logic of scientific discovery, Chapter 3 of his, A realist theory of science. New York: Harvester Wheatsheaf.
4. Blaug, M. (1968). Economic theory in retrospect (pp. 30–32). Homewood: Richard D. Irwin.
5. Boulding, K. E. (1971a). Economics as a moral science. In F. R. Glabe (Ed.), Boulding collected papers (Vol. 3). Boulder: Association of University Press.