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Harris، Lement (1978). Harold M. Ware (1890-1935): Agricultural Pioneer, U.S.A. and U.S.S.R. (Occasional Paper No. 30). American Institute for Marxist Studies. ص. 3 (Farm Research Inc), 4 (weekly), 5 (Margret Stevens), 8 (Clarissa Smith), 10 (draftsman), 16 (24 Case tractors), 18 (Toikino), 37 (Jessica Smith), 36–41 (fundraising), 43–45 (1929–1930, 45–58 (US tour), 59 (pamphlet), 59–68 (Farm Research Inc), 68 (death). مؤرشف من الأصل في 2019-12-15. اطلع عليه بتاريخ 2018-08-06.