1. Health Services and' Mental Health Administration Publication 73-8704 (1973).
2. Royal College of Physicians Smoking and Health (1962).
3. Royal College of Physicians Smoking and Health Now (1971).
4. U.S. Public Health Report 1103 (1964).
5. BOCK, F.G., NATURE OF TUMOR-PROMOTING AGENTS IN TOBACCO PRODUCTS, CANCER RESEARCH 28: 2363 (1968).