1. C. G. Barnes (1970 ), "Medical Disorders in Obstetric Practice ", 3rd Edn , Blackwell Scientific Publications, Oxford, p.11 .
2. Pregnancy and congenital heart disease
3. I. Donald (1972 ), "Practical Obstetric Problems ", 4th Edn. Lloyd-Luke (Medical Books) Ltd., London. p.107 .
4. EVALUATION OF ADEQUATE ANTEPARTUM CARE FOR THE CARDIAC PATIENT