1. 3rd World Congress of Human Reproduction, Berlin (Excerpta Medica, Amsterdam, 1981).
2. Edwards, R.G. & Steptoe, P.C. J. Reprod. Fert. Suppl. 22, 121 (1975); Lancet i, 683 (1970).
3. Edwards, R.G. Conception in the Human Female (Academic, London, 1980).
4. Kratochwil, A., Urban, G. & Friedrich, F. Ann. Chir. Gynaec. Fenniae 61, 211 (1972).
5. de Crespigny, L.J. Ch., O'Herlihy, C., Hoult, I.J. & Robinson, H.P. Fert. Steril. 35, 25 (1981).