Although each main-set volume of Terrorism: 1st Series contains its own volume-specific index, this comprehensive Index places all the Index info from the last fifty main-set volumes into one index volume. Furthermore, the volume-specific indexes are only subject indexes, whereas five different indexes appear within this one comprehensive index: the subject index, an index organized according to the title of the document, an index based on the name of the document's author, an index correlated to the document's year, and a subject-by-year index. This one all-encompassing Index thus provides users with multiple ways to conduct research into four years' worth of Terrorism: 1st Series volumes.