Auksarapuk Puriwathana และ Piyasan Praserthdam. (2012) Effect of impurities in ethylene gas on the catalytic activity of ziegler-natta catalyst and polyethylene properties. Chulalongkorn University:ม.ป.ท.Auksarapuk Puriwathana และ Piyasan Praserthdam. 2012. Effect of impurities in ethylene gas on the catalytic activity of ziegler-natta catalyst and polyethylene properties. ม.ป.ท.:Chulalongkorn University;Auksarapuk Puriwathana และ Piyasan Praserthdam. Effect of impurities in ethylene gas on the catalytic activity of ziegler-natta catalyst and polyethylene properties. ม.ป.ท.:Chulalongkorn University, 2012. Print.