Maram Saudy และ Safwan Khedr. (2016) Evaluation of Normal and Modified Asphalt According to Conventional and Modern Grading Systems. ISEC Press:ม.ป.ท.Maram Saudy และ Safwan Khedr. 2016. Evaluation of Normal and Modified Asphalt According to Conventional and Modern Grading Systems. ม.ป.ท.:ISEC Press;Maram Saudy และ Safwan Khedr. Evaluation of Normal and Modified Asphalt According to Conventional and Modern Grading Systems. ม.ป.ท.:ISEC Press, 2016. Print.