@inbook{NBERc11822,
 Crossref = "NBERgros09-1",
 title = "Physical Activity: Economic and Policy Factors",
 author = "Melayne M. McInnes and Judith A. Shinogle",
 BookTitle = "Economic Aspects of Obesity",
 Publisher = "University of Chicago Press",
 pages = "249-282",
 year = "2011",
 month = "April",
 URL = "http://www.nber.org/chapters/c11822",
}
@book{NBERgros09-1,
 title = "Economic Aspects of Obesity",
 author = "Michael Grossman and Naci H. Mocan",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "University of Chicago Press",
 year = "2011",
 URL = "http://www.nber.org/books/gros09-1",
}