Andrew M. Watson, ‘Back to Gold – and Silver’, Economic History Review 20:1 (1967), 11-12; Jasim Alubudi, Repertorio Bibliográfico del Islam (Madrid: Vision Libros, 2003), 194. 3 Watson, ‘Back to Gold – and Silver’, 17-18. 4 David Graeber, Debt: The First 5,000 Years ...