http://www.lboro.ac.uk/gawc/rb/rb205.html Global City-Firm Networks PhD work – R Wall, mentor Dr. G.A. v.d. Knaap. Acknowledgements - Michiel Raats and Wilfred Sleegers. Faculty of Applied Economics, Erasmus University Rotterdam. Client , Netherlands Environmental Assessment Agency (MNP). A = total connections. B = basic materials connections. C = manufacturing connections. D = trade connections E = producer services connection