@techreport{NBERw13133,
 title = "How Do Workplace Smoking Laws Work? Quasi-Experimental Evidence from Local Laws in Ontario, Canada",
 author = "Christopher Carpenter",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "13133",
 year = "2007",
 month = "May",
 URL = "http://www.nber.org/papers/w13133",
}