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.
This paper on institutional frameworks is very helpful for getting more information about the topic. It is offering both detailed information and links to further reading material in each of its sections.
IEES (2006): Challenges in Developing an Institutional Framework. Wolhusen: International Ecological Engineering Society (IEES) URL [Accessed: 11.04.2019]