Lamont, Douglas
Blackwell Publishers, 1996
Buku Referensi
Elex Media Komputindo, 1994
Buku Teks
Kurtz, David L.
The Dryden Press , 1981
Buku Teks
Alex Soemadji Nitisemito
Ghalia Indonesia, 1984
Buku Teks
Alex Soemadji Nitisemito
Ghalia Indonesia, 1984
Buku Teks