Levitt, S. D., & Porter, J. (1999). Sample selection in the estimation of air bags and seat belt effectiveness. National Bureau of Economic Research.
Čikaški stil citiranja (17. izdanje)Levitt, Steven D., i Jack Porter. Sample Selection in the Estimation of Air Bags and Seat Belt Effectiveness. Cambridge: National Bureau of Economic Research, 1999.
MLA način citiranja (9. izdanje)Levitt, Steven D., i Jack Porter. Sample Selection in the Estimation of Air Bags and Seat Belt Effectiveness. National Bureau of Economic Research, 1999.
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