@article{zhang2011emergy, title = {Emergy analysis of the urban metabolism of Beijing} author = {Zhang, Yan; Yang, Zhifeng; Liu, Gengyuan; Yu, Xiangyi}, journal = {Ecological Modelling}, url = {http://www.sciencedirect.com/science/article/pii/S0304380010004886}, doi = {10.1016/j.ecolmodel.2010.09.017}, year = {2011} }