@article{BorckSchrauth2020,
  author    = {Rainald Borck and Philipp Schrauth},
  title     = {Population density and urban air quality},
  journal   = {Regional science and urban economics},
  volume    = {86},
  doi       = {10.1016/j.regsciurbeco.2020.103596},
  year      = {2020},
}