Hart, W. L. (1969). Essentials of algebra. Prindle, Weber and Schmidt, Inc.
Lua i Stíl Chicago (17ú heag.)Hart, William L. Essentials of Algebra. Boston, Massachusetts: Prindle, Weber and Schmidt, Inc, 1969.
Lua MLA (9ú heag.)Hart, William L. Essentials of Algebra. Prindle, Weber and Schmidt, Inc, 1969.
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