McGraw-hill book , 1950
Buku Teks
Beach, Dale S., author
Macmillan, 1975
Buku Teks
edited by Robert Teviot Livingston and Stanley H. Milberg
Colombia University Press , 1957
Buku Teks
Prentice-Hall, 1949
Buku Teks
Hunter, Guy, author
University of London Press, 1961
Buku Teks