Gopalan, C.
World Health Organization, 1994
Buku Teks
Gopalan, C.
World Health Organization , 1994
Buku Teks
Coedes, George
Univesity of California Press, 1969
Buku Teks
London : IP Publishing Ltd
Majalah, Jurnal, Buletin
Hall, D.G.E.
Macmillan, 1970
Buku Teks