Udomsri Ngowsiri. (1988) Structure and development of reproductive system in Achatina fulica. Mahidol University,:ม.ป.ท.Udomsri Ngowsiri. 1988. Structure and development of reproductive system in Achatina fulica. ม.ป.ท.:Mahidol University,;Udomsri Ngowsiri. Structure and development of reproductive system in Achatina fulica. ม.ป.ท.:Mahidol University, 1988. Print.