Books, Brochures, and Chapters>Book:  Salisbury , John of , The Metalogicon of John Salisbury, Univ of California Press, Retrieved on 2012-01-13

Source Material [books.google.com]

Books, Brochures, and Chapters>Book:  Salisbury , John of (2009-11-01), The Metalogicon: A Twelfth-Century Defense of the Verbal and Logical Arts of the Trivium, Paul Dry Books, Retrieved on 2011-06-17

Source Material [wadsworth.com]