@inbook{NBERc9664,
 Crossref = "NBEReast80-1",
 title = "Toward a More General Economic Model of Fertility Determination: Endogenous Preferences and Natural  Fertility",
 author = "Richard Easterlin and Robert Pollak and Michael L. Wachter",
 BookTitle = "Population and Economic Change in Developing Countries",
 Publisher = "University of Chicago Press",
 pages = "81-150",
 year = "1980",
 URL = "http://www.nber.org/chapters/c9664",
}
@book{NBEReast80-1,
 title = "Population and Economic Change in Developing Countries",
 author = "Richard A. Easterlin",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "University of Chicago Press",
 year = "1980",
 URL = "http://www.nber.org/books/east80-1",
}