TI - NEeded population research PT - JOUR DP - 1939 TA - Journal of the American Medical Association pages = {268-269}, VI - 112 IP - 3 AID - 10.1001/jama.1939.02800030078043 [doi] 4100 - http://dx.doi.org/10.1001/jama.1939.02800030078043 SO - Journal of the American Medical Association January 21, 1939 112(3):268