Cita APA (7a ed.)
(1987). X/OPEN Portability Guide: System V Specification Commands and Utilities. Elsevier.
Cita Chicago Style (17a ed.)
X/OPEN Portability Guide: System V Specification Commands and Utilities. Amsterdam: Elsevier, 1987.
Cita MLA (9a ed.)
X/OPEN Portability Guide: System V Specification Commands and Utilities. Elsevier, 1987.
Precaución: Estas citas no son 100% exactas.