WHO, 1996
Buku Teks
Goldhammer, Robert, author
Holt, Rinehart and Winston, 1980
Buku Teks
Bigge, Morris L.
Harper & Row , 1982
Buku Teks
by Christoph Stocker, Ingrid Davids; Karl Heinz Bonath, Wolfgang Hieber
Wiley Eastern, 1979
Buku Teks
Briggs, Freda, author
Allen & Unwin, 1997
Buku Teks