APA
Brown Lester R,, . (1991). State of the world, 1991. New Delhi: World Watch Institute.
Chicago
Brown Lester R,, . 1991. State of the world, 1991. New Delhi: World Watch Institute.
Harvard
Brown Lester R,, . (1991). State of the world, 1991. New Delhi: World Watch Institute.
MLA
Brown Lester R,, . State of the world, 1991. New Delhi: World Watch Institute. 1991.