TY - SER TI - British Medical Journal : Vol. 302 [6780 - 6792] April - June SN - 09598138 U1 - 616 PY - 1991/// CY - London PB - BMJ KW - MEDICAL SCIENCES KW - Medicine N1 - With Index UR - https://www.bmj.com/archive/print/1991 ER -