example of voluntary work with his own sweat, pushing a wheelbarrow at a building site or cutting sugar cane in the fields with a machete." People's Weekly
on 6 March 2019. Retrieved 2019-03-10. Drew, James (2016-04-20). "US lawmakers want cost data for building 194 more F-22s". Flightglobal.com (به انگلیسی)
(2014). The European Union and Occupied Palestinian Territories: State-building without a state. Routledge. ISBN 978-1-317-91529-4. Bregman, Ahron (2016)