1. Adamowics, W., Boxall, P., & Louviere, J. (1998). Stated preference approaches for measuring passive use values: Choice experiments and contingency valuation. American Journal of Agricultural Economics, 80(1), 64–75.
2. Adams, J. B., Bossio, R. J., & Rohan, P. (1989). Accounting for contributed services. Norwalk: FASB.
3. Alcock, P., Millar, R., Hall, K., Lyon, F., Nicholls, A., & Gabriel, M. (2012). Start up and growth: National Evaluation of the Social Enterprise Investment Fund (SEIF). London: Department of Health Policy Research Programme.
4. Andreoni, J. (1990). Impure altruism and donations to public goods: A theory of warm-glow giving. Economic Journal, 100(401), 464–477.
5. Arrow, K., Solow, R., Portney, P. R., Leamer, E. E., Radner, R., & Schuman, H. (1993). Report of the NOAA panel on contingent valuation.