Siritorn Charoensuk. (1994) Ring a modification of 20-hydroxyecdysone. Ramkhamhaeng University,:ม.ป.ท.Siritorn Charoensuk. 1994. Ring a modification of 20-hydroxyecdysone. ม.ป.ท.:Ramkhamhaeng University,;Siritorn Charoensuk. Ring a modification of 20-hydroxyecdysone. ม.ป.ท.:Ramkhamhaeng University, 1994. Print.