1. The information in discretionary outlays: Advertising, research, and development;Bublitz;The Accounting Review,1989
2. Econometric measurement of the duration of advertising effect on sales;Clarke;Journal of Marketing Research,1976
3. Intangible Capital and Rates of Return, Effects of Research and Development on Profitability;Clarkson,1977
4. The political economy of the pharmaceutical industry;Comanor;Journal of Economic Literature,1986
5. Investment Under Uncertainty;Dixit,1994