Engelman, R., & LeRoy, P. (1993). Sustaining water: Population and the future of renewable water supplies. Washington: Population Action International.
Cita Chicago (17th ed.)Engelman, Robert, i Pamela LeRoy. Sustaining Water: Population and the Future of Renewable Water Supplies. Washington: Population Action International, 1993.
Cita MLA (8th ed.)Engelman, Robert, i Pamela LeRoy. Sustaining Water: Population and the Future of Renewable Water Supplies. Washington: Population Action International, 1993.
Atenció: Aquestes cites poden no estar 100% correctes.