Tienke Ambar Wulandari
[publisher not identified], 2001
Buku Teks
Redfield, Robert
Westview Press, 1991
Buku Teks
Black, Robert H.
AGPS, 1972
Buku Teks
MacLaine, Allan H.
Twayne Publishers, 1965
Buku Teks
Ennis, Robert Hugh
Prentice-Hall, 1996
Buku Teks