APA-viite

Heck, H. (1993). UNIX: Working with UNIX and XENIX. Prisma computer courses.

Chicago-tyylinen lähdeviittaus

Heck, Hans-Josef. UNIX: Working with UNIX and XENIX. Great Britain: Prisma computer courses, 1993.

MLA-viite

Heck, Hans-Josef. UNIX: Working with UNIX and XENIX. Prisma computer courses, 1993.