Gaya APA

Harms, E. et al (1992). Wordperfect 5.1 (Software training & reference (STAR) series) . USA: Boyd & Fraser Publishing Company.

Gaya MLA

Harms, Edward. et al. "Wordperfect 5.1 (Software training & reference (STAR) series)". USA: Boyd & Fraser Publishing Company, 1992. Text.