1. "Heroin Century", Tom Carnwath, Ian Smith; Routledge, 2002 Page 6
2. "A Hundred-Year Habit", Ian Scott; History Today, Vol. 48, June 1998
3. "Drug Use, Policy and Management", Richard E. Isralowitz, Darwin Telias; Praeger Publishers, 1998 Page 39
4. "Drug Use, Policy and Management" Richard E. Isralowitz, Darwin Telias; Praeger Publishers, 1998 Page 39
5. "Opium: A History ", Martin H. Levinson; ETC.: A Review of General Semantics, Vol. 55, 1998
6. "Drug Use, Policy and Management", Richard E. Isralowitz, Darwin Telias; Praeger Publishers, 1998 Page 39
7."Drugs and Drug Policy in America: A Documentary History",Steven R. Belenko; Greenwood Press, 2000 Page 4
8."Drugs in America: A Social History, 1800-1980", Wayne Morgan; Syracuse University Press, 1982 page 27