Gaya APA
Annual editions: Environment 02/03. (2002).
Guillord:
Mc Graw-Hill.
Gaya Chicago
Annual editions: Environment 02/03.
.
Guillord:
Mc Graw-Hill,
2002.
Buku.
Gaya MLA
Annual editions: Environment 02/03.
.
Guillord:
Mc Graw-Hill,
2002.
Buku.
Gaya Turabian
Annual editions: Environment 02/03.
Guillord:
Mc Graw-Hill,
2002.
Buku.