PEARSON ROBERT E. /współaut./ 192,158 zob. DRUG Drug information services: two operational models. Model 1. A complete drug information service in a hospital. By Charles M.King, Jr., and Betty A.Hellums. Model.2. A regional drug information network. By Vera F. Thudium, and Robert E.Pearson. Rockville 1972 Department of Health Education and Welfare,Public Health Service 4° 3. XII, 265, ilustr.