Page 7: © Clive Pratt – Entomologist.
Page 15: By permission of the Provost and Scholars of King’s College, Cambridge.
Page 160: Thanks to Roger Penrose.
Page 183: Ramon Llull, Ars brevis VIIIs. Palma de Mallorca, BP MS998. Virtual Library of Bibliographic Heritage. Spanish Ministry of Education, Culture and Sport.