Armstrong, E. A. (1976). Saint Francis, nature mystic: The derivation and significance of the nature stories in the Franciscan Legend. University of California Press.
Παραπομπή σε μορφή Chicago (17η εκδ.)Armstrong, Edward Allworthy. Saint Francis, Nature Mystic: The Derivation and Significance of the Nature Stories in the Franciscan Legend. Berkeley: University of California Press, 1976.
Παραπομπή σε μορφή MLA (8th εκδ.)Armstrong, Edward Allworthy. Saint Francis, Nature Mystic: The Derivation and Significance of the Nature Stories in the Franciscan Legend. University of California Press, 1976.
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