Murray, Les A., author
Angus & Robertson, 1983
Buku Teks
Greenwood, Susan, author
Berg, 2000
Buku Teks
Silberg, Richard, author
Harcourt, Brace & World, 1967
Buku Teks
Burns, James McGregor, author
Prentice-Hall, 1972
Buku Teks
Newell, Kenneth W., author
World Health Organization, 1975
Buku Teks