(Non-Muslims who couldn't pay the taxes were sent to Labor Camps) Nowill, Sidney E. P. (December 2011). Constantinople and Istanbul: 72 Years of Life in Turkey. Matador. p. 77. ISBN978-1848767911."..., and those unable to pay were packed off to a camp at Askale, near Erzerum - an area cooler than Moscow in the winter - where they were put to work breaking stones."
Peretz, Don (January 1994). The Middle East Today. Greenwood Publishing Group. p. 179."..., and if the sale failed to produce the required amount, the owners were sent to forced labor camps run by the Ministry of Public Works."