Cita APA (7th ed.)

Ritchie, C. (1997). Operating systems (3rd ed.). Letts Educational.

Cita Chicago (17th ed.)

Ritchie, C. Operating Systems. 3rd ed. London: Letts Educational, 1997.

Cita MLA (9th ed.)

Ritchie, C. Operating Systems. 3rd ed. Letts Educational, 1997.