| 1 | Todd, N. J, Todd, J., From Eco-Cities to Living Machines: Principles of Ecological Design, Nort Atlantic Books Berkeley, california, 1993, s.75. |
| 2 | S. Edgar David, “How Does Your Rooftop Grow?, Temple University Ambler, The Philadelphia Inquirer, March 8, 2002, Features Magazine, Edition: City-D, Page E01. |