@inbook{NBERc10409,
 Crossref = "NBERaesm75-3",
 title = "Classification of Economic Indicators: An Alternative Approach",
 author = "Ivy Broder and Gregory Schoepfle",
 BookTitle = "Annals of Economic and Social Measurement, Volume 4, number 3",
 Publisher = "NBER",
 pages = "435-445",
 year = "1975",
 month = "July",
 URL = "http://www.nber.org/chapters/c10409",
}
@book{NBERaesm75-3,
 title = "Annals of Economic and Social Measurement, Volume 4, number 3",
 author = "Sanford V. Berg, editor",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "NBER",
 year = "1975",
 URL = "http://www.nber.org/books/aesm75-3",
}