1. Organisations Evolving;Aldrich,2006
2. Competing technologies, increasing returns, and lock-in by historical events;Arthur;Economic Journal,1989
3. ASG, 2013. A Shade Greener goes from Strength to Strength.
4. BEP, 2012. Birmingham Environmental Partnership—Who We Are.
5. BERR, 2007. Department of Business, Enterprise and Regulatory Reform.