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Mario M. Pérez-Ruiz (2003). El Manuscrito Voynich (in Spanish). Barcelona: Océano Ambar. ISBN84-7556-216-7.CS1 maint: Unrecognized language (link)
Lawrence and Nancy Goldstone (2005). The Friar and the Cipher: Roger Bacon and the Unsolved Mystery of the Most Unusual Manuscript in the World. New York: Doubleday. ISBN0-7679-1473-2.
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