@inbook{NBERc4266,
 Crossref = "NBERgutt70-1",
 title = "The Effective Yield Concept",
 author = "Jack M. Guttentag and Morris Beck",
 BookTitle = "New Series on Home Mortgage Yields Since 1951",
 Publisher = "NBER",
 pages = "143-160",
 year = "1970",
 URL = "http://www.nber.org/chapters/c4266",
}
@book{NBERgutt70-1,
 title = "New Series on Home Mortgage Yields Since 1951",
 author = "Jack M. Guttentag and Morris Beck",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "NBER",
 year = "1970",
 URL = "http://www.nber.org/books/gutt70-1",
}