Parker, Steve
Parragon, 2000
Buku Referensi
Anderson, Edwin P.
D.B. Taraporevala Sons, 1970
Buku Teks
Muhammad Irfan
1997
UI - Skripsi Membership
Basu, S.K.
New Delhi : Oxford and IBH, c1989
Buku Teks
Gerling, Heinrich
Wiley Eastern Limited, 1982
Buku Teks