Sombat Thanawan. (1992) A study of foaming of rubber. Mahidol University,:ม.ป.ท.Sombat Thanawan. 1992. A study of foaming of rubber. ม.ป.ท.:Mahidol University,;Sombat Thanawan. A study of foaming of rubber. ม.ป.ท.:Mahidol University, 1992. Print.