@inbook{NBERc3140,
 Crossref = "NBERunkn50-1",
 title = "Introduction to "Studies in Income and Wealth"",
 author = "Morris A. Copeland",
 BookTitle = "Studies in Income and Wealth",
 Publisher = "UMI",
 pages = "1-20",
 year = "1950",
 URL = "http://www.nber.org/chapters/c3140",
}
@book{NBERunkn50-1,
 title = "Studies in Income and Wealth",
 author = "Elwyn T. Botinell (Chairman), editing committee and Morris A. Copeland, editing committee and Simon Kuznets, editing committee and Martha Anderson, editor and Lillian Epstein, editor",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "UMI",
 year = "1950",
 URL = "http://www.nber.org/books/unkn50-1",
}