Bethesda, Md. : U.S. Dept. of Health, Education, and Welfare, Public Health Service, National Institutes of Health, National Institute of Child Health and Human Development, Center for Population Research ; Washington : for sale by the Supt. of Docs., U.S. Govt. Print. Off., 
xi, 250 pages ; 24 cm.
Center for Population Research monograph.
DHEW publication ; no. (NIH) 75-565. "Supported by the Center for Population Research, National Institute of Child Health and Human Development, under contract number NO1-HD2-2708 and by the Office of Economic Opportunity under contract number B 00-5209 with TRACOR, inc., Austin, Texas." Includes index.