Hansen, W. G. (1971). St. Francis of Assisi: Patron of the environment. Franciscan Herald Press.
Lua i Stíl Chicago (17ú heag.)Hansen, Warren G. St. Francis of Assisi: Patron of the Environment. Chicago, Ill.: Franciscan Herald Press, 1971.
Lua MLA (8ú heag.)Hansen, Warren G. St. Francis of Assisi: Patron of the Environment. Franciscan Herald Press, 1971.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.