RT Journal T1 BRazil JF Journal of the American Medical Association JO Journal of the American Medical Association YR 1959 FD September 19 VO 171 IS 3 SP 326 OP 326 DO 10.1001/jama.1959.73010210006020 UL http://dx.doi.org/10.1001/jama.1959.73010210006020 AB