Natelson, Morris, author
Fairchild Publications, 1962
Buku Teks
Kellerman, Barbara, author
Harvard Business School Press, 2004
Buku Teks
Wallace-Murphy, Tim, author
Watkins, 2006
Buku Teks
Mitchell, Wesley C., author
National Bereau of Economic Reseach, 1951
Buku Teks
Mitchell, Wesley C., author
National Bureau of Economic Research, 1951
Buku Teks