Williams, M. (1990). Wetlands: A threatened landscape. Basil Blackwell.
Lua i Stíl Chicago (17ú heag.)Williams, Michael. Wetlands: A Threatened Landscape. Oxford: Basil Blackwell, 1990.
Lua MLA (9ú heag.)Williams, Michael. Wetlands: A Threatened Landscape. Basil Blackwell, 1990.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.