MCGRAW-HILL. (1992). Mcgraw-hill encyclopedia of science and technology 8: GEO-HYS. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)MCGRAW-HILL. Mcgraw-hill Encyclopedia of Science and Technology 8: GEO-HYS. New York: McGraw-Hill, 1992.
Lua MLA (9ú heag.)MCGRAW-HILL. Mcgraw-hill Encyclopedia of Science and Technology 8: GEO-HYS. McGraw-Hill, 1992.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.