سفاف م. ., يعقوب غ., and سليمان ح. “Using the Policy Analysis Matrix (PAM) to Study Changes in Subsidies on the Apple Crop in Syria During the Period (2010-2021)”. Tishreen University Journal -Biological Sciences Series, vol. 44, no. 4, Sept. 2022, pp. 79-96, https://journal.tishreen.edu.sy/index.php/bioscnc/article/view/12600.