@inbook{NBERc1058, Crossref = "NBERunkn58-2", title = "A Method of Identifying Chronic Low-Income Groups from Cross-Section Survey Data", author = "Eleanor M. Snyder", BookTitle = "An Appraisal of the 1950 Census Income Data", Publisher = "Princeton University Press", pages = "323-356", year = "1958", URL = "http://www.nber.org/chapters/c1058", } @book{NBERunkn58-2, title = "An Appraisal of the 1950 Census Income Data", author = "Conference on Research in Income and Wealth", institution = "National Bureau of Economic Research", type = "Book", publisher = "Princeton University Press", year = "1958", URL = "http://www.nber.org/books/unkn58-2", }