Não informado. (1989). Laser Focus World. Pennwell Publishing.
Chicago (17e ed.) BronvermeldingNão informado. Laser Focus World. Tulsa, Okla: Pennwell Publishing, 1989.
MLA (8e ed.) BronvermeldingNão informado. Laser Focus World. Pennwell Publishing, 1989.
Let op: Deze citaties zijn niet altijd 100% accuraat.