@article{GudipudiFluschnikRosetal.2016,
  author    = {Venkata Ramana Gudipudi and Till Fluschnik and Anselmo Garcia Cantu Ros and Carsten Walther and J{\"u}rgen Kropp},
  title     = {City density and CO2 efficiency},
  journal   = {Energy policy : the international journal of the political, economic, planning, environmental and social aspects of energy},
  volume    = {91},
  pages     = {352 -- 361},
  doi       = {10.1016/j.enpol.2016.01.015},
  year      = {2016},
}