1. Levit K.R., Lazenby H.C., Cowan C., Letsch S.W.: National Health Expenditures. Health Care Financ. Rev. 13: 29–54, 1991.
2. Culyer A.J.: Cost containment in Europe. Health Care Financ. Rev. Annu. (SuppL): 21-32, 1989.
3. LaVange L., Silverman H.: Outpatient prescription drug utilization and expenditure patterns of noninstitutionalized aged medicare beneficiaries. National Medical Care Utilization and Expenditure Survey, Series B, Descriptive Report No. 12. DHHS Pub. No. 86-20212. Office of Research and Demonstrations, Health Care Finance Administration, U.S. Govt. Printing Office, Washington D.C., April 1987.
4. Gurwitz J.H., Avorn J.: The ambiguous relation between aging and adverse drug reactions. Ann. Intern. Med. 114:956–966, 1991.
5. Williamson J., Chopin J.M.: Adverse reactions to prescribed drugs in the elderly: a multicenter investigation. Age Ageing 9: 73–80, 1980.