Kramer MD, Taylor V, Hickok DE, Daling JR, Vaughan TL, Hollenbach KA. Maternal smoking and placenta previa. Epidemiology. 1991 May;2(3):221-3.
Kramer MD, Taylor V, Hickok DE, Daling JR, Vaughan TL, Hollenbach KA. Maternal smoking and placenta previa. Epidemiology. 1991 May;2(3):221-3.