WORLD BOOK. (1990). WORLD BOOK'S SCIENCE DESK REFERENCE. WORLD BOOK INC.
Lua i Stíl Chicago (17ú heag.)WORLD BOOK. WORLD BOOK'S SCIENCE DESK REFERENCE. CHICAGO: WORLD BOOK INC, 1990.
Lua MLA (9ú heag.)WORLD BOOK. WORLD BOOK'S SCIENCE DESK REFERENCE. WORLD BOOK INC, 1990.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.