Cita APA (7a ed.)

Sin autor & AT&T. (1990). UNIX System V, release 4: Programmer's guide : POSIX conformance. [S.n.].

Cita Chicago Style (17a ed.)

Sin autor y AT&T. UNIX System V, Release 4: Programmer's Guide : POSIX Conformance. Englewood Cliffs: [S.n.], 1990.

Cita MLA (9a ed.)

Sin autor y AT&T. UNIX System V, Release 4: Programmer's Guide : POSIX Conformance. [S.n.], 1990.