Bainbridge, F.A.
Longmans, Green , 1919
Buku Teks
Macey, Robert I.
Prentice-Hall, 1968
Buku Teks
Grossman, Charles J.
Sulzburger & Graham, 1995
Buku Teks
Mitchell, Philip H.
McGraw-Hill, 1956
Buku Teks
Wright, Samson
Oxford University Press, 1928
Buku Referensi