1. Bureau of Consumer Protection (1977)Staff Report on Advertising of Ophthalmic Goods and Services and Proposed Trade Regulation Rule. Federal Trade Commission.
2. Bureau of Consumer Protection (1980)State restrictions on Vision Care providers: The effects on Consumers. Federal Trade Commission.
3. Bureau of Economics (1980)Effects of Restrictions on Advertising and Commercial Practice in the Professions: The Case of Optometry. Federal Trade Commission.
4. Central Statistical Office (1991)Annual Abstract of Statistics. London: HMSO.