1. Barriers to new competition;Bain,1946
2. The pioneer brand hypothesis and other topics: Product markets with assymetric information about product quality;Conrad,1982
3. Information and consumer behavior;Nelson;Journal of Political Economy,1970
4. Product differentiation advantages of pioneering brands;Schmalensee;American Economic Review,1982
5. Bureau of Economics, Sales promotion and product differentiation in two prescription drug markets;U.S. Federal Trade Commission,1977