Cita APA (7th ed.)

Worldwatch Institute & Brown, L. R. (1999). State of the world 1999: A Worldwatch Institute report on progress toward a sustainable society. W. W. Norton & Company.

Cita Chicago (17th ed.)

Worldwatch Institute i Lester Russell Brown. State of the World 1999: A Worldwatch Institute Report on Progress Toward a Sustainable Society. New York ; London: W. W. Norton & Company, 1999.

Cita MLA (8th ed.)

Worldwatch Institute i Lester Russell Brown. State of the World 1999: A Worldwatch Institute Report on Progress Toward a Sustainable Society. W. W. Norton & Company, 1999.