APA
Heutel G., National Bureau of Economic Research & Ruhm C. J. (2013). Air pollution and procyclical mortality. Cambridge: NBER.
Chicago
Heutel Garth, National Bureau of Economic Research and Ruhm Christopher J. 2013. Air pollution and procyclical mortality. Cambridge: NBER.
Harvard
Heutel G., National Bureau of Economic Research and Ruhm C. J. (2013). Air pollution and procyclical mortality. Cambridge: NBER.
MLA
Heutel Garth, National Bureau of Economic Research and Ruhm Christopher J. Air pollution and procyclical mortality. Cambridge: NBER. 2013.