Helzer. The Ecology and Management of Prairies in the Central United States. University of Iowa Press.
Lua i Stíl Chicago (17ú heag.)Helzer. The Ecology and Management of Prairies in the Central United States. University of Iowa Press.
Lua MLA (9ú heag.)Helzer. The Ecology and Management of Prairies in the Central United States. University of Iowa Press.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.