Krug, Ronald S.
Springer-Verlag, 1992
Buku Teks
Krug, Ronald S.
Springer-Verlag, 1992
Buku Teks
Kirk-Greene, C.W.E.
Foulsham, 1992
Buku Teks
Marcus, George E., editor
The University of Chicago Press, 1986
Buku Teks
Gravetter, Frederick J.
Thomson Learning, 2000
Buku Teks