Comstock GW and Livesay VT: Subcutaneous fat determinations from a community-wide chest X-ray survey in Muscogee County, Georgia. Ann NY Acad Sci 110:475-491, 1963.Comstock GW, Edwards LB, Philip RN and Winn WA: A comparison in the United States of America of two tuberculins, PPD-S and RT 23. Bull WHO 31:161-170, 1964.