Smith C, Crowther C, Beilby J, et al. The impact of nausea and vomiting on women: a burden of early pregnancy. The Australian & new Zealand Journal of Obstetrics & Gynecology. 2000, 40 (4), 397 401.
Attard CL, Kohli MA, Coleman S, et al. The burden of illness of severe nausea and vomiting of pregnancy in the United States. American Journal of Obstetrics & Gynecology. 2002, 186 (suppl), 220 227.