Artikel Jurnal
Kementerian Luar Negeri Republik Indonesia
[publisher not identified], 2011
Buku Teks
Slate, Floyd O.
Cornell University, 1974
Buku Referensi
Berry, R. Albert, author
Md. Johns Hopkins University Press , 1979
Buku Teks
World Health Organization, 1994
Buku Teks