World Health Organization
Regional Office for South-East Asia, 1989
Buku Teks
Kessner, David M.
Institute of Medicine , 1973
Buku Teks
Miller, Robert
The Population Council, 1997
Buku Referensi
edited by Conrad Seipp. With a pref. by Cecil G. Sheps
The John Hopkins University Press , 1981
Buku Teks
Cab International, 1996
Buku Teks