1. International Organization for Standardization ISO 14040 series (1997–2003).
2. Pré Consultants, The Eco-indicator 99 a damage oriented method for Life Cycle Assessment: Methodology report, 3rd revised ed. (1999) available at http://www.pre.nl/eco-indicator99/ei99-reports.htm.
3. P. White, S. Belletire, L. St. Pierre, Okala: learning ecological design, Okala Ecological Design, Industrial Design Society of America (2004) available at http://www.idsa.org/webmodules/webforms/okala_order_form.html.
4. BEES® 4.0 Building for Environmental and Economic Sustainability: Technical Manual and User Guide;Lippiatt,2007