Farley, John E.
Prentice-Hall, 1992
Buku Teks SO
Nobbs, Jack
Macmillan Education, Ltd., 1989
Buku Teks SO
Finsterbusch, Kurt
McGraw-Hill, 2006
Buku Teks SO
Kurt Finsterbusch, editor
McGraw-Hill, 2007
Buku Teks SO
Fulcher, James
Oxford University Press, 2007
Buku Teks SO