Carson, Robert C.
Longman, 1997
Buku Teks
World Health Organization
World Health Organization, 1981
Buku Teks
Gupta, Giri Raj
Allyn and Bacon, 1993
Buku Teks
edited by Teresa Scheild and Tony Brown
Cambridge University Press, 2010
Buku Teks
Golightley, Malcom
Learning matters Ltd., 2008
Buku Teks