Runyon, Richard P.
Addison-Wesley , 1968
Buku Teks
Runyon, Richard P.
Addison Wesley Publ., 1967
Buku Teks
Scott, W. Richard, 1932-
Holt,Rinehart and winston, 1970
Buku Teks
Bagozzi, Richard P.
Open University Press , 2002
Buku Teks
Kirk-Greene, C. W. E.
Foulsham, 1992
Buku Teks