Schlosser, Eric (2014). Command and Control Nuclear Weapons, the Damascus Accident, and the Illusion of Safety (1st ed.). Penguin Group USA. p. 204. ISBN 978-0143125785. They began by poring through the Air Force's Bombing Encyclopedia, a compendium of more than eighty thousand potential targets located throughout the world. The book gave a brief description of each target, its longitude and latitude and elevation, its category—such as military or industrial, airfield or oil refinery—and its "B.E. number," a unique eight-digit identifier. From that lengthy inventory, twelve thousand candidates in the Soviet Union, the Eastern bloc, and China were selected. 978-0143125785