1. Relief of pain in labour;Beazley, J.M.; Leaver, E.P.; Morewood, J.H.M.; Bircumshaw, J.;Lancet,1967
2. Measurement of pain;Huskisson, E.C.;Lancet,1974
3. The reliability of a linear analogue for evaluating pain;Revill, S.I.; Robinson, J.O.; Rosen, M.; Hogg, M.I.J.;Anaesthesia,1976
4. Epidural nerve block;Steel, G.C.,1977
5. The assessment of the analgesic effect in labour of pethidine and 50 per cent nitrous oxide in oxygen (Entonox);Holdcroft, A.; Morgan, M.;Journal of Obstetrics and Gynaecology of the British Commonwealth,1974