Columbia subject headings:
Didius Julianus, Emperor of Rome, 137-193.
Emperors--Rome--Biography.
Pescennius Niger, Emperor of Rome, -194.
Rome--History--Empire, 30 B.C.-284 A.D.
Rome--Politics and government--30 B.C.-284 A.D.
Severus, Lucius Septimius, Emperor of Rome, 146-211.
Harvard subject headings:
Princeton subject headings:
Didius Julianus, Emperor of Rome, 137-193.
Emperors--Rome--Biography.
Rome--History--Empire, 30 B.C.-284 A.D.
Rome--Politics and government--30 B.C.-284 A.D.
Severus, Lucius Septimius, Emperor of Rome, 146-211.