United States. Department of Labor Bureau of Labor Statistics. (1988). Supplement to employment and earnings. U.S. Department of Labor.
芝加哥风格引文United States. Department of Labor Bureau of Labor Statistics. Supplement to Employment and Earnings. U.S: U.S. Department of Labor, 1988.
MLA引文United States. Department of Labor Bureau of Labor Statistics. Supplement to Employment and Earnings. U.S. Department of Labor, 1988.
警告：这些引文格式不一定是100％准确.