Cressey, George Babcock, 1896-1963
McGraw-Hill, 1951
Buku Teks
Cressey, George Babcock, 1896-1963
Whittlesey house, McGraw-Hill book company inc., 1944
Buku Teks
edited by Norton Sydney Ginsburg ... [and others]
Prentice-Hall, 1958
Buku Teks
Routledge, 1992
Buku Teks
East, W. Gordon
Methuen, 1950
Buku Teks