Hartley, W. H., & Vincent, W. S. (1967). Tests for use with American civics. Harcourt, Brace & World.
Lua i Stíl Chicago (17ú heag.)Hartley, William Harrison, agus William Shafer Vincent. Tests for Use with American Civics. New York: Harcourt, Brace & World, 1967.
Lua MLA (8ú heag.)Hartley, William Harrison, agus William Shafer Vincent. Tests for Use with American Civics. Harcourt, Brace & World, 1967.
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