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.
Chicago-referens (17:e uppl.)Worldwatch Institute och 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.
MLA-referens (8:e uppl.)Worldwatch Institute och Lester Russell Brown. State of the World 1999: A Worldwatch Institute Report on Progress Toward a Sustainable Society. W. W. Norton & Company, 1999.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.