TY - BOOK ED - US Health Education and Welfare. Dept.of Public Health Service TI - Net Differences in Interview Data on Chronic Conditions and Information Derived from Medical Records T2 - Vital and Health Statistics.Series 2: Data Evalution and Methods Research, no. 57 PY - 1973/// CY - Rockville Md. PB - National Centre forHealth Statistics KW - Health occupation KW - US ER -