Ramos O'hara, J. A. (1996). Indicators of environmental impact: Plan of the improvement of the high watershed of the Virilla river, Costa Rica.
Chicago-tyylinen lähdeviittausRamos O'hara, Jorge A. Indicators of Environmental Impact: Plan of the Improvement of the High Watershed of the Virilla River, Costa Rica. 1996.
MLA-viiteRamos O'hara, Jorge A. Indicators of Environmental Impact: Plan of the Improvement of the High Watershed of the Virilla River, Costa Rica. 1996.
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