Nana Bassuk, et al. eds. “Structural Soil: An Innovative Medium Under Pavement that Improves Street Tree Vigor” 1998 ASLA Annual Meeting Proceedings, Urban Horticulture Institute, Cornell University. 1998. p183 – p185.

Online: http://www.hort.cornell.edu/uhi/outreach/csc/article.pdf

Jason Grabosky and Nina Sassuk, “A New Urban Tree Soil to Safely Increase Rooting Volumes Under Sidewalks” Journal of Arboriculture 21(4). July 1995. p187.

Jason Grabosky and Nina Sassuk, 1995. ibid. p187.

Jason Grabosky, et al, eds. “Structural Soils, A New Medium to Allow Urban Trees to Grow in Pavement” Landscape Architecture Technical Information Series (LATIS). 2000 p12.

Online: http://www.asla.org/latis/pdf/Structural_soils_updated081202.pdf

Kim Sorvig, “Soil Under Pressure” Landscape Architecture. June. 2001. v91. n6. 40.