Pornpen Gamnarai และ Sasichai Kangsadalampai. (2007) Polymorphism of the pi class glutathione S-transferase and susceptibility to peptic ulceration. Thammasat University,:ม.ป.ท.Pornpen Gamnarai และ Sasichai Kangsadalampai. 2007. Polymorphism of the pi class glutathione S-transferase and susceptibility to peptic ulceration. ม.ป.ท.:Thammasat University,;Pornpen Gamnarai และ Sasichai Kangsadalampai. Polymorphism of the pi class glutathione S-transferase and susceptibility to peptic ulceration. ม.ป.ท.:Thammasat University, 2007. Print.