Siewers, A. K. The green otherworlds of early medieval literature: Alfred K. Siewers. The Cambridge companion to literature and the environment.(2014).
Lua i Stíl Chicago (17ú heag.)Siewers, Alfred K. "The Green Otherworlds of Early Medieval Literature: Alfred K. Siewers." The Cambridge Companion to Literature and the Environment.(2014) .
Lua MLA (8ú heag.)Siewers, Alfred K. "The Green Otherworlds of Early Medieval Literature: Alfred K. Siewers." The Cambridge Companion to Literature and the Environment.(2014), .
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.