Cita APA (7th ed.)

(1990). Unix system v release 4, user's guide. Unix System Laboratories, Inc.

Cita Chicago (17th ed.)

Unix System V Release 4, User's Guide. USA: Unix System Laboratories, Inc, 1990.

Cita MLA (9th ed.)

Unix System V Release 4, User's Guide. Unix System Laboratories, Inc, 1990.