Mark Waterstone, J Deirdre Murphy, Susan Bewley, Charles Wolfe
Waterstone M, Murphy J D, Bewley S, Wolfe C.
Incidence and predictors of severe obstetric morbidity: case-control studyCommentary: Obstetric morbidity data and the need to evaluate thromboembolic disease
BMJ 2001; 322 :1089
doi:10.1136/bmj.322.7294.1089