RT Journal T1 DEnmark JF Journal of the American Medical Association JO Journal of the American Medical Association YR 1959 FD July 18 VO 170 IS 12 SP 1443 OP 1443 DO 10.1001/jama.1959.63010120014021 UL http://dx.doi.org/10.1001/jama.1959.63010120014021 AB