Columbia subject headings:
IS (Organization)
Religious fanaticism--Iraq.
Religious fanaticism--Syria.
Terrorism--Religious aspects--Islam.
Harvard subject headings:
IS (Organization)--History.
Religious fanaticism--Iraq--Islam.
Religious fanaticism--Syria--Islam.
Terrorism--Religious aspects--Islam
Princeton subject headings:
IS (Organization)
Religious fanaticism--Iraq.
Religious fanaticism--Syria.
Terrorism--Religious aspects--Islam.