Oxon: Routledge Elkington, J., “Cannibals with Forks: the Triple Bottom Line of 21st Century Business”, Capstone, 1997 Kollmuss, A., Zink, H., Polycarp, C. (2008) Making Sense of the Voluntary Carbon Markets: A comparison of carbon offset standards. Germany: WWF Maltzman, R. & Shirley, D. (2011) Green Project Management. Boca Raton: Taylor & Francis Rebitzer, G., Ekvall, T., Frischknecht, R., Hunkeler, D., Norris, G., Rydberg, T., Schmidt, W.P., Suh, S., Weidema, B.P., Pennington, D.W. (2004) ‘Life cycle assessment Part 1: Framework, goal and scope definition, inventory analysis, and applications’, Environmental International 30 pp.701-720. REFERENCES