World Health Organization, 1975
Buku Teks
Tarone, Elaine, author
Oxford University Press, 1991
Buku Teks
edited for the International Epidemiological Association and the World Health Organization by Basil S. Hetzel
Oxford University Press, 1978
Buku Teks
Baah, Asamoah
World Health Organization, 1995
Buku Teks
Grant, James P., author
Overseas Development Council , 1978
Buku Teks