Bulliet, Richard W.; Bulliet, Richard; Crossley, Pamela Kyle; Daniel R. Headrick; Steven W. Hirsch; Lyman L. Johnson; David Northrup (1 January 2010). The Earth and Its Peoples: A Global History. Cengage Learning. p. 694. ISBN978-1-4390-8475-5. 19 जून 2013 को मूल से पुरालेखित. अभिगमन तिथि: 16 April 2012.
Bulliet, Richard W.; Bulliet, Richard; Crossley, Pamela Kyle; Daniel R. Headrick; Steven W. Hirsch; Lyman L. Johnson; David Northrup (1 January 2010). The Earth and Its Peoples: A Global History. Cengage Learning. p. 694. ISBN978-1-4390-8475-5. 19 जून 2013 को मूल से पुरालेखित. अभिगमन तिथि: 16 April 2012.