edited by W.G. Walker
University of Queensland Press, 1972
Buku Teks
Marius, Richard
McGraw-Hill, 1988
Buku Teks
Pierson, Frank C.
McGraw-Hill, 1959
Buku Teks SO
Rudolph, Frederick
Alfred A. Knopf, 1962
Buku Teks
Heffernan, James A. W.
W.W. Norton & Company, 1990
Buku Referensi