Butlin, R. A., & Roberts, N. (1995). Ecological relations in historical times: Human impact and adaptation. Blackwell.
Lua i Stíl Chicago (17ú heag.)Butlin, R. A., agus Neil Roberts. Ecological Relations in Historical Times: Human Impact and Adaptation. Oxford: Blackwell, 1995.
Lua MLA (9ú heag.)Butlin, R. A., agus Neil Roberts. Ecological Relations in Historical Times: Human Impact and Adaptation. Blackwell, 1995.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.