Klein, S. (1983). Our world today. Steck-Vaughn.
Cita Chicago (17th ed.)Klein, Stanley. Our World Today. Steck-Vaughn, 1983.
Cita MLA (9th ed.)Klein, Stanley. Our World Today. Steck-Vaughn, 1983.
Atenció: Aquestes cites poden no estar 100% correctes.