Holloway, William Vernon, author
McGraw-Hill , 1951
Buku Teks
Bingham, Richard D., author
McGraw-Hill, 1991
Buku Teks
Chapman, R.J.K., author
George Allen and Unwin, 1984
Buku Teks
edited by Terence Emmons and Wayne S. Vucinich
Cambridge University Press, 2011
Buku Teks
Basil Blackwell, 1948
Buku Teks