Gaya APA

Encyclopaedia Britannica : 1989 Britannica book of the year :events of 1988 /By encyclopaedia Britannica. (1989). Chigago: Encyclopaedia Britannica,1989.

Gaya MLA

Encyclopaedia Britannica : 1989 Britannica book of the year :events of 1988 /By encyclopaedia Britannica. . Chigago: Encyclopaedia Britannica,1989, 1989. Text.