"The Green Blue Heart"(PDF). smi-teesvalley.co.uk. Stockton-Middlesbrough Initiative. Archived from the original(PDF) on 4 October 2011. Retrieved 12 June 2009.
"The Green Blue Heart"(PDF). smi-teesvalley.co.uk. Stockton-Middlesbrough Initiative. Archived from the original(PDF) on 4 October 2011. Retrieved 12 June 2009.