Gaya APA
Ball, A, R. (1989).
Modern politics and government, 4th ed. .
Houndmills & London:
Houndmills & London Macmillan Education Ltd.
Gaya MLA
Ball, Alan, R..
"Modern politics and government, 4th ed. ".
Houndmills & London:
Houndmills & London Macmillan Education Ltd,
1989.
Buku.