↑ Guinn, Kenny C. (2002). Pattern and Palette of Place: A Landscape and Aesthetics Master Plan for the Nevada State Highway System. Carson City, Nevada: Nevada Department of Transportation.
↑ Yuan, Zhen (2014). China's Grain for Green Program A Review of the Largest Ecological Restoration and Rural Development Program in the World. Cham: Springer International Publishing. ISBN978-3-319-11504-7.