TY  - JOUR
A1  - Kramer, M.S.
A1  - Platt, R.
A1  - Yang, H.
A1  - Joseph, K.S.
A1  - Wu Wen, S.
A1  - Morin, L.
A1  - Usher, R.H.
T1  - Secular trends in preterm birth. A hospital-based cohort study
Y1  - 1998
DO  - 10.1001/jama.280.21.1849
JF  - JAMA: The Journal of the American Medical Association
VL  - 280
IS  - 21

ER  -