APA
SIMPSON A., . (1993). Mastering wordperfect 6 for DOS. SAN FRANCISCO: SYBEX.
Chicago
SIMPSON ALAN, . 1993. Mastering wordperfect 6 for DOS. SAN FRANCISCO: SYBEX.
Harvard
SIMPSON A., . (1993). Mastering wordperfect 6 for DOS. SAN FRANCISCO: SYBEX.
MLA
SIMPSON ALAN, . Mastering wordperfect 6 for DOS. SAN FRANCISCO: SYBEX. 1993.