Sparger, Jennifer. "Asphalt Antidote : "Living" Roofs Absorb Runoff," in Federal Reserve Bank of Richmond. "Summer 2004, Volume 8, Number 3," Econ Focus (Federal Reserve Bank of Richmond) (Summer 2004) : 13-13. https://fraser.stlouisfed.org/title/3941/item/476926/toc/503827 , accessed on March 29, 2024.