Cita APA (7th ed.)

Sommerville, I., & Sawyer, P. (1977). Requirements engineering: A good practice guide. Wiley.

Cita Chicago (17th ed.)

Sommerville, Ian, i Pete Sawyer. Requirements Engineering: A Good Practice Guide. Chichester, Eng. ; New York ; New Delhi: Wiley, 1977.

Cita MLA (8th ed.)

Sommerville, Ian, i Pete Sawyer. Requirements Engineering: A Good Practice Guide. Wiley, 1977.