1. Bell SC (1988) Synthesis and secretion of proteins by the endometrium and decidua. In: Chapman MG, Grudzinskas JG, Chard T (eds) Implantations. Springer-Verlag, London, pp 95–108
2. Bellman O, Tebbe J, Lang N, Baur MP (1980) Determination of SP1 and hPL for predicting perinatal asphyxia. In: Klopper A, Genazzani A, Crosignani PG (eds) The human placenta: proteins and hormones. Academic Press, London, pp 99–108
3. Brambati B, Lanzani A, Tului L (1991) Ultrasound and biochemical assessments of first trimester pregnancy. In: Chapman M, Grudzinskas JG, Chard T (eds) The embryo. Springer-Verlag, London, pp 181–194
4. Chard T (1991) Frequency of implantation of early pregnancy loss in natural cycles. In: Bailliere’s Clinical Obstetrics and Gynaecology. Bailliere-Tindall, London, vol 5, pp 179–189
5. Chard T, Grudzinskas JG (1987) Early pregnancy factor. Biol Res Preg 8:53–56