@inbook{NBERc7083,
 Crossref = "NBERwise98-2",
 title = "4. Does Medicare Eligibility Affect Retirement?",
 author = "Brigitte C. Madrian and Nancy Beaulieu",
 BookTitle = "Inquiries in the Economics of Aging",
 Publisher = "University of Chicago Press",
 pages = "109-131",
 year = "1998",
 month = "January",
 URL = "http://www.nber.org/chapters/c7083",
}
@book{NBERwise98-2,
 title = "Inquiries in the Economics of Aging",
 author = "David A. Wise",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "University of Chicago Press",
 year = "1998",
 URL = "http://www.nber.org/books/wise98-2",
}