APA aipamena

Williams, S., & Poulton, R. (1999). Twins and maternal smoking: Ordeals for the fetal origins hypothesis? A cohort study. British Medical Journal.

Chicago Style aipamena

Williams, Sheila, and Richie Poulton. Twins and Maternal Smoking: Ordeals for the Fetal Origins Hypothesis? A Cohort Study. British Medical Journal, 1999.

MLA aipamena

Williams, Sheila, and Richie Poulton. Twins and Maternal Smoking: Ordeals for the Fetal Origins Hypothesis? A Cohort Study. British Medical Journal, 1999.