Sampson, Robert C.
McGraw-Hill , 1965
Buku Teks
Krug, Ronald S.
Springer-Verlag, 1992
Buku Teks
Krug, Ronald S.
Springer-Verlag, 1992
Buku Teks
Gravetter, Frederick J.
Thomson Learning, 2000
Buku Teks
Gravetter, Frederick J.
Wadsworth/Thomson Learning, 2004
Buku Teks