Southworth, G. V. D., & Southworth, J. V. D. (1958). A work book on Long ago in the Old World. Iroquois Pub. Co..
Lua i Stíl Chicago (17ú heag.)Southworth, Gertrude Van Duyn, agus John Van Duyn Southworth. A Work Book on Long Ago in the Old World. Syracuse, N.Y.: Iroquois Pub. Co., 1958.
Lua MLA (8ú heag.)Southworth, Gertrude Van Duyn, agus John Van Duyn Southworth. A Work Book on Long Ago in the Old World. Iroquois Pub. Co., 1958.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.