Grupe, F. H. (1990). Microcomputer applications: Using WordPerfect 5.0, Lotus 1-2-3, and dBase III Plus. W.C. Brown.
Dyfyniad Arddull ChicagoGrupe, Fritz H. Microcomputer Applications: Using WordPerfect 5.0, Lotus 1-2-3, and DBase III Plus. Dubuque, Iowa: W.C. Brown, 1990.
Dyfyniad MLAGrupe, Fritz H. Microcomputer Applications: Using WordPerfect 5.0, Lotus 1-2-3, and DBase III Plus. W.C. Brown, 1990.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.