Hall, Thomas L.
The John Hopkins University Press , 1969
Buku Teks
Green, Andrew
Oxford University Press, 2007
Buku Teks
World Health Organization, 1978
Buku Teks
Taylor, Carl E.
The John Hopkins University Press , 1968
Buku Teks
Akhtar, Shahid
International Development Research Centre, 1975
Buku Teks