!Coconut coir<ref>Urban Drainage and Flood Control District. (2010). “Bioretention.” <http://udfcd.org/criteria-manual/volume-3/t-03-bioretention/> (Mar. 15, 2018).</ref>
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!Coconut coir<ref>Rheaume, A., Hinman, C., and Ahearn, D. (2015). “A Synthesis of Bioretention Research in Pacific Northwest.” Herrera, <http://www.modularwetlands.com/new/wp-content/uploads/2015/11/2-Bioretention-Synthesis-2015-DAhearn.pdf></ref>