Article · Journal · 1974
D. A. WARRELL, N. M. Davidson, L. D. Omerod, H. M. Pope, B J Watkins, Brian Greenwood and 1 more
BMJ
Read it10.1136/bmj.4.5942.437
as printed: D. A. Warrell
as printed: B. J. Watkins
as printed: B. M. Greenwood