Willis K.J & McElwain, J. (2002). The evolution of plants. Oxford University Press.
Lua i Stíl Chicago (17ú heag.)Willis K.J agus J.C McElwain. The Evolution of Plants. New York: Oxford University Press, 2002.
Lua MLA (9ú heag.)Willis K.J agus J.C McElwain. The Evolution of Plants. Oxford University Press, 2002.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.