Cita APA (7a ed.)

Göckel, H. (1989). WordPerfect 5.0. Hüthig.

Cita Chicago Style (17a ed.)

Göckel, Harald. WordPerfect 5.0. Heidelberg: Hüthig, 1989.

Cita MLA (8a ed.)

Göckel, Harald. WordPerfect 5.0. Hüthig, 1989.