World Resources Institute. (1993). The 1993 Information Please Environmental Almanac. Houghton Mifflin.
Chicago-čujuhus (17. p.)World Resources Institute. The 1993 Information Please Environmental Almanac. Boston, New York: Houghton Mifflin, 1993.
MLA-čujuhus (9. p.)World Resources Institute. The 1993 Information Please Environmental Almanac. Houghton Mifflin, 1993.
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