عماد مصطفى القرعان (2011): الغاز الحيوي. المركز الوطنى للبحث والارشاد الزراعى
Perspectives are different frameworks from which to explore the knowledge around sustainable sanitation and water management. Perspectives are like filters: they compile and structure the information that relate to a given focus theme, region or context. This allows you to quickly navigate to the content of your particular interest while promoting the holistic understanding of sustainable sanitation and water management.