Dyfyniad APA

Brown, L. R. (1997). State of the world 1998: A world watch institute report on progress toward a sustainable society. W.W. Norton & Company.

Dyfyniad Arddull Chicago

Brown, Lester R. State of the World 1998: A World Watch Institute Report on Progress Toward a Sustainable Society. New York: W.W. Norton & Company, 1997.

Dyfyniad MLA

Brown, Lester R. State of the World 1998: A World Watch Institute Report on Progress Toward a Sustainable Society. W.W. Norton & Company, 1997.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.