APA Style
WordPerfect shell version 4.0 : user's guide. (1993).
Utah:
Wordperfect Corporation.
Chicago Style
WordPerfect shell version 4.0 : user's guide.
1.
Utah:
Wordperfect Corporation,
1993.
Text.
MLA Style
WordPerfect shell version 4.0 : user's guide.
1.
Utah:
Wordperfect Corporation,
1993.
Text.
Turabian Style
WordPerfect shell version 4.0 : user's guide.
Utah:
Wordperfect Corporation,
1993.
Print.