1. Epidemiology of birth before 28 weeks of gestation;Macfarlane;Brit Med Bull,1988
2. Pregnancy outcome at 24–31 weeks' gestation: mortality;Wariyar;Arch Dis Child,1989
3. High incidence of preterm birth and early losses in pregnancy after an vitro fertilisation;Lancaster;Br Med J,1986
4. Care of preterm babies in the first hour;Halliday;Care Crit Ill,1988
5. Prematurity;Halliday,1992