Cita APA (7th ed.)

Summers, D. C. S. (1997). Quality. Prentice Hall.

Cita Chicago (17th ed.)

Summers, Donna C. S. Quality. Upper Saddle River, N.J: Prentice Hall, 1997.

Cita MLA (9th ed.)

Summers, Donna C. S. Quality. Prentice Hall, 1997.