Empey, LaMar T.
Aldine Publishing Company, 1971
Buku Teks
Macintyre, Stuart
Australian Goverment, 1947
Buku Teks
Christopher Alexander...[et al.]
Oxford University Press, 1975
Buku Teks
Furnivall, JS
Solidaridad publishing house, 1974
Buku Teks
Yeager, Rodger
Westview Press, 1989
Buku Teks