Gaya APA
VS Cobol II Application Programing Guide. (1986).
USA:
IBM Corporation.
Gaya Chicago
VS Cobol II Application Programing Guide.
.
USA:
IBM Corporation,
1986.
Text.
Gaya MLA
VS Cobol II Application Programing Guide.
.
USA:
IBM Corporation,
1986.
Text.
Gaya Turabian
VS Cobol II Application Programing Guide.
USA:
IBM Corporation,
1986.
Print.