Benham, Frederic
New York, N.Y. Sir Issac Pitman 1941,
Buku Teks
Livesey, Frank
Longman , 1989
Buku Teks
Mitchell, Philip H.
McGraw-Hill, 1956
Buku Teks
Ross, Alf
Longmans, Green , 1947
Buku Teks
edited by Thomas J. Anderson, Abraham L. Gitlow and Daniel E. Diamond
Richard D. Irwin, 1959
Buku Teks