Li และ Wang. (1992) A study of factors resulting in low birth weight in Ratchaburi hospital. Mahidol University,:ม.ป.ท.Li และ Wang. 1992. A study of factors resulting in low birth weight in Ratchaburi hospital. ม.ป.ท.:Mahidol University,;Li และ Wang. A study of factors resulting in low birth weight in Ratchaburi hospital. ม.ป.ท.:Mahidol University, 1992. Print.