@inbook{NBERc0940,
 Crossref = "NBERzarn67-1",
 title = "TIME SPAN OF FORECASTS AND PREDICTIVE ACCURACY",
 author = "Victor Zarnowitz",
 BookTitle = "An Appraisal of Short-Term Economic Forecasts",
 Publisher = "UMI",
 pages = "60-82",
 year = "1967",
 URL = "http://www.nber.org/chapters/c0940",
}
@book{NBERzarn67-1,
 title = "An Appraisal of Short-Term Economic Forecasts",
 author = "Victor Zarnowitz",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "UMI",
 year = "1967",
 URL = "http://www.nber.org/books/zarn67-1",
}