Langer, W. L. (1952). An encyclopedia of world history: Ancient, medieval, and modern, chronologically arranged (Revised edition.). Houghton Mifflin.
Lua i Stíl Chicago (17ú heag.)Langer, William L. An Encyclopedia of World History: Ancient, Medieval, and Modern, Chronologically Arranged. Revised edition. Boston: Houghton Mifflin, 1952.
Lua MLA (8ú heag.)Langer, William L. An Encyclopedia of World History: Ancient, Medieval, and Modern, Chronologically Arranged. Revised edition. Houghton Mifflin, 1952.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.