U.S. Citizenship and Immigration Services. (2012). Civics flash cards for the naturalization test (Rev. 02, 2102.). U.S. Dept. of Homeland Security, U.S. Citizenship and Immigration Services : For sale by the Supt. of Docs., U.S. G.P.O..
Chicago Style (17th ed.) CitationU.S. Citizenship and Immigration Services. Civics Flash Cards for the Naturalization Test. Rev. 02, 2102. [Washington, D.C.]: U.S. Dept. of Homeland Security, U.S. Citizenship and Immigration Services : For sale by the Supt. of Docs., U.S. G.P.O., 2012.
MLA引文U.S. Citizenship and Immigration Services. Civics Flash Cards for the Naturalization Test. Rev. 02, 2102. U.S. Dept. of Homeland Security, U.S. Citizenship and Immigration Services : For sale by the Supt. of Docs., U.S. G.P.O., 2012.