David Zurdo and Ángel Gutiérrez have together written more than twenty books, outstanding amongst which is El último secreto de Da Vinci, which has been translated into eight languages and sold more than 100,000 copies. David Zurdo is a regular contributor  to the written press, as well as radio and televisión. Ángel Gutiérrez is the author of dozens of articles and is also a translator. He has appeared on numerous radio programmes and many televisión programmes.