Gaya APA

Vienna:IUGG,1991. (). [s.l]: [s.n].

Gaya Chicago

Vienna:IUGG,1991. . [s.l]: [s.n], . Text.

Gaya MLA

Vienna:IUGG,1991. . [s.l]: [s.n], . Text.

Gaya Turabian

Vienna:IUGG,1991. [s.l]: [s.n], . Print.