Holden, Paul E., author
McGraw-Hill, 1968
Buku Teks
Business Publications, 1981
Buku Teks
Cerami, Charles A., author
Prentice-Hall, 1957
Buku Teks
Hodges, Henry G., author
Houghton Miffiln, 1955
Buku Teks
Batty, J
The English Languange Book Society, 1979
Buku Teks