Tobacco smoking, pregnancy estrogens, and birth weight.

MLA

Petridou, E., et al. “Tobacco Smoking, Pregnancy Estrogens, and Birth Weight.” Epidemiology (Cambridge, Mass.), vol. 1, no. 3, May 1990, pp. 247–50. EBSCOhost, https://doi.org/10.1097/00001648-199005000-00011.

APA

Petridou, E., Panagiotopoulou, K., Katsouyanni, K., Spanos, E., & Trichopoulos, D. (1990). Tobacco smoking, pregnancy estrogens, and birth weight. Epidemiology (Cambridge, Mass.), 1(3), 247–250. https://doi.org/10.1097/00001648-199005000-00011

Chicago

Petridou, E, K Panagiotopoulou, K Katsouyanni, E Spanos, and D Trichopoulos. 1990. “Tobacco Smoking, Pregnancy Estrogens, and Birth Weight.” Epidemiology (Cambridge, Mass.) 1 (3): 247–50. doi:10.1097/00001648-199005000-00011.