Kittiporn Nitetwittayanukool และ Soorathep Kheawhom. (2006) Study on economic and environment efficiency of offset and digital printing systems. Chulalongkorn University:ม.ป.ท.Kittiporn Nitetwittayanukool และ Soorathep Kheawhom. 2006. Study on economic and environment efficiency of offset and digital printing systems. ม.ป.ท.:Chulalongkorn University;Kittiporn Nitetwittayanukool และ Soorathep Kheawhom. Study on economic and environment efficiency of offset and digital printing systems. ม.ป.ท.:Chulalongkorn University, 2006. Print.