Most of the sources listed in this technical appendix are also listed in the Basic Source listings at the end of each chapter or section. Listings under the chapter on the nature and extent of drug use pertain to the consequences and patterns of illegal drug use. The references pertain to such topics as the relationship between drug use and crime; the link between drug use, drug trafficking, and violent crime; how drug use harms families and schools; and how illegal drugs threaten the health and productivity of users. Also discussed are why people use illicit drugs, methods of ingestion, drug user characteristics, and changing patterns of drug use in the United States. References for the chapter on the illegal drug business relate to the source of illegal drugs, how they reach the United States, factors in drug prices, the organization of the illegal drug business, and money laundering. References for other chapters pertain to responses to the drug problem and drugs and the justice system.