Cita APA (7th ed.)
Spiegel, H. (1986). Cornerstone: Foundations for writing (1a. ed.). D. C. Heath and Company.
Cita Chicago (17th ed.)
Spiegel, Harriet. Cornerstone: Foundations for Writing. 1a. ed. Estados Unidos: D. C. Heath and Company, 1986.
Cita MLA (9th ed.)
Spiegel, Harriet. Cornerstone: Foundations for Writing. 1a. ed. D. C. Heath and Company, 1986.
Atenció: Aquestes cites poden no estar 100% correctes.