1. National High Blood Pressure Education Program Working Group report on high blood pressure in pregnancy;National Institutes of Health,2000
2. Hypertension in pregnancy;American College of Obstetricians and Gynecologists;ACOG Tech Bull,1996
3. Hypertensive disorders in twin versus singleton gestations;Sibai;Am J Obstet Gynecol,2000
4. Report of the Canadian hypertension society consensus conference: 1. Definitions, evaluation and classification of hypertensive disorders in pregnancy;Helewa;CMAJ,1997
5. The classification and definition of the hypertensive disorders of pregnancy;Davey;Am J Obstet Gynecol,1988