1. Tripplett, J.E., Bosworth, B.P., 2000. Productivity in the services sector. Paper to the American Economic Association, January 2000, Boston, MA.
2. Metals Economics Group, 1993. Environmental Costs and Issues in Gold Exploration, Halifax, Nova Scotia, July 1993.
3. Metals Economics Group. Corporate Exploration Strategies, Halifax, Nova Scotia, various issues.
4. Statistics Canada, 1997. Environmental Protection Expenditures in the Business Sector, 1996 and 1997 (revised), Ottawa, August 2000.
5. Parry, I.W.H., 1999. Productivity trends in the natural resource industries. In: Simpson, R.D. (Ed.), Productivity in Natural Resource Industries; Improvement through Innovation. Resources for the Future, Washington, DC.