1. Aristotle. (1995). Politics (Books I and II) (T. J. Saunders, Trans.). Oxford: Clarendon Press.
2. Aristotle. (2000). Nicomachean ethics (R. Crisp, Ed. & Trans.). New York: Cambridge University Press.
3. Ayres, R. U., & Ayres, L. W. (Eds.). (2001). A handbook of industrial ecology. Cheltenham: Edward Elgar.
4. Ayres, R. U., Bergh, J. C. J. M. van den, & Gowdy, J. M. (1998). Viewpoint: Weak versus strong sustainability (Tinbergen Institute Discussion Papers, 98-103/3). Amsterdam/Rotterdam: Tinbergen Institute.
5. Barthlott, W., & Neinhuis, C. (1997). Purity of the sacred lotus, or escape from contamination in biological surfaces. Planta, 202, 1–8.