APA引文

U.S. Bureau of the Census. (1951). Census of manufactures, 1949, Purto Rico. s.n.

芝加哥风格引文

U.S. Bureau of the Census. Census of Manufactures, 1949, Purto Rico. Washington: s.n, 1951.

MLA引文

U.S. Bureau of the Census. Census of Manufactures, 1949, Purto Rico. s.n, 1951.

警告：这些引文格式不一定是100％准确.