Bos, A. P., & Ferwerda, R. (2008). Aristotle, On the life-bearing spirit (De spiritu): A discussion with Plato and his predecessors on pneuma as the instrumental body of the soul. Brill.

Bos, A. P., and R. Ferwerda. Aristotle, On the Life-bearing Spirit (De Spiritu): A Discussion with Plato and His Predecessors on Pneuma as the Instrumental Body of the Soul. Leiden ; Boston: Brill, 2008.

Bos, A. P., and R. Ferwerda. Aristotle, On the Life-bearing Spirit (De Spiritu): A Discussion with Plato and His Predecessors on Pneuma as the Instrumental Body of the Soul. Brill, 2008.