Bagley, Desmond, author
Collins, 1965
Buku Teks
Cronin, A. J.
Little, Brown and Company, 1948
Koleksi Publik
Simons, David G.
New York: Doubleday, 1960
Buku Teks
D de G Jones
Texas : NACE, 1976
Buku Teks
editors, Rui Calcada, Raimundo Delgado, Antonio Campos e Matos
CRC Press, Taylor & Francis Group, 2009
Buku Teks