Orapan Chalernwong และ Chainarong Srikunwong. (2014) Numerical Analysis for Dynamic Characteristics of Sphere Drop Test on Oil-based Clay Backing Material. Thai Society of Mechanical Engineers:ม.ป.ท.Orapan Chalernwong และ Chainarong Srikunwong. 2014. Numerical Analysis for Dynamic Characteristics of Sphere Drop Test on Oil-based Clay Backing Material. ม.ป.ท.:Thai Society of Mechanical Engineers;Orapan Chalernwong และ Chainarong Srikunwong. Numerical Analysis for Dynamic Characteristics of Sphere Drop Test on Oil-based Clay Backing Material. ม.ป.ท.:Thai Society of Mechanical Engineers, 2014. Print.