Bates, Robin
Cambridge University Press, 1974
Buku Teks
Nove, Alec
George Allen and Unwin, 1973
Buku Teks
Levy, Haim, author
Prentice-Hall, 1878
Buku Teks
Levy, Haim, author
Prentice-Hall, 1990
Buku Teks
Levy, Haim, author
Prentice-Hall, 1986
Buku Teks