Questionnaires completed by 50 scholars from ll nations provided information for the volume and ideas influencing its content and organization. The section on concepts first explores the meaning of violence, political crime, guerrilla warfare, assassination, victims of terrorism, and motivation. Also examined are acts and actors in terrorism and its extraordinary qualities such as weapons, time and place, and deliberate violation of basic human rules of conduct. A review of theoretical work emphasizes theories on the etiology of terrorism, addressing frustration-aggression explanations for political violence, the influence of totalitarian rule, terrorists' theories, psychological theories, and terrorism as surrogate warfare. The book also considers conspiracy, communications, sociological, and environmental theories. The guide to data bases identifies chronologies and other data collections compiled by governments and private research organizations in the United States and several European countries. This section discusses institutes and journals for the study of terrorism, as well as problems regarding data reliability and uniformity. The directory of terrorist organizations and movements involved in political violence covers some l,500 groups in approximately l25 nations and territories. The bibliography is divided into 20 major categories, including bibliographies, concepts, regime terrorism, insurgent terrorism, terrorist activities by region and country, international terrorism, the terrorist personality, victimology, countermeasures, and special types of terrorism. Tables, diagrams, and indexes to the bibliography are supplied.