1. The mathematical theory of epidemics;Bailey,1957
2. The diffusion of an innovation among physicians;Coleman;Sociometry,1957
3. Industrial structure and the nature of innovative activity;Dasgupta;Economic Journal,1980
4. Uncertainty, industrial structure, and the speed of R&D;Dasgupta;Bell Journal of Economics,1980
5. The diffusion of process innovations;Davies,1979