Nick Beeching, Geoff Gill.
Wiley-Blackwell, 2014
Buku Teks
Eddleston, Michael
New York Oxford Univ. Press 2002,
Buku Referensi
InternaPublishing, 2014
Prosiding
Eddelson, Michael, author
Oxford University Press, 1999
Buku Referensi
World Health Organization, [date of publication not identified]
Buku Teks