Engelman, R., & LeRoy, P. (1993). Sustaining water: Population and the future of renewable water supplies. Washington: Population Action International.
Lua i Stíl Chicago (17ú heag.)Engelman, Robert, agus Pamela LeRoy. Sustaining Water: Population and the Future of Renewable Water Supplies. Washington: Population Action International, 1993.
Lua MLA (8ú heag.)Engelman, Robert, agus Pamela LeRoy. Sustaining Water: Population and the Future of Renewable Water Supplies. Washington: Population Action International, 1993.
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