U.S. Bureau of the Census. (1950). Classified index of occupations and industries: 1950 census of population. U.S. Govt. Print. Off.
芝加哥风格引文U.S. Bureau of the Census. Classified Index of Occupations and Industries: 1950 Census of Population. Washington: U.S. Govt. Print. Off, 1950.
MLA引文U.S. Bureau of the Census. Classified Index of Occupations and Industries: 1950 Census of Population. U.S. Govt. Print. Off, 1950.
警告：这些引文格式不一定是100％准确.