1. Standard specifications for topsoil used for landscaping purposes, ASTM D5258-13;ASTM (American Society for Testing and Materials),2013
2. General specification for building, Section 25 landscape work;ASD (Architectural Services Department),2012
3. Standard specification for urban infrastructure works, Section 9 landscape;ACT (Australian Capital Territory),2002
4. Stability of landscape trees in engineered and conventional urban soil mixes;Bartens;Urban Forestry & Urban Greening,2010
5. Nitrogen-total;Bremner,1996