Worldwatch Institute & Brown, L. R. (1993). State of the world, 1993: A Worldwatch Institute report on progress toward a sustainable society. Norton.

Worldwatch Institute and Lester Russell Brown. State of the World, 1993: A Worldwatch Institute Report on Progress Toward a Sustainable Society. New York: Norton, 1993.

Worldwatch Institute and Lester Russell Brown. State of the World, 1993: A Worldwatch Institute Report on Progress Toward a Sustainable Society. Norton, 1993.