APA aipamena

(1999). State of the world 1999: A worldwatch Institute report on progress toward a sustainable society. New York: Norton.

Chicago Style aipamena

State of the World 1999: A Worldwatch Institute Report On Progress Toward a Sustainable Society. New York: Norton, 1999.

MLA aipamena

State of the World 1999: A Worldwatch Institute Report On Progress Toward a Sustainable Society. New York: Norton, 1999.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.