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<ref>Richard Hammond (2017). Evaluating Green and Blue Roof Opportunities in Canadian Cities. UWSpace. http://hdl.handle.net/10012/11463</ref>
<ref>Richard Hammond (2017). Evaluating Green and Blue Roof Opportunities in Canadian Cities. UWSpace. http://hdl.handle.net/10012/11463</ref>
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<ref>https://www.pwdplanreview.org/manual/chapter-4/4.6-blue-roofs</ref>
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