Langer, W. L. (1952). An encyclopedia of world history: Ancient, medieval, and modern, chronologically arranged (Revised edition.). Houghton Mifflin.
Chicago-referens (17:e uppl.)Langer, William L. An Encyclopedia of World History: Ancient, Medieval, and Modern, Chronologically Arranged. Revised edition. Boston: Houghton Mifflin, 1952.
MLA-referens (8:e uppl.)Langer, William L. An Encyclopedia of World History: Ancient, Medieval, and Modern, Chronologically Arranged. Revised edition. Houghton Mifflin, 1952.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.