1. New drug development in the United States from 1963 to 1990;Di Masi;Clinical Pharmocology and Therapeutics,1991
2. Pricing, profits, and technological progress in the pharmaceutical industry;Scherer;Journal of Economic Perspectives,1993
3. Prescription drugs: spending controls in four European countries;United States General Accounting Office,1995
4. The role of the research-based pharmaceutical industry in medical progress in the United States;Kaitin;Health Care Policy,1993