Anthony, Robert N. (Robert Newton), 1916-2006, author
McGraw-Hill/Irwin,, 2007
Buku Teks
Brech, E.F.L., author
Longmans, Green & Co. , 1957
Buku Teks
Brech, E.F.L., author
Longman , 1970
Buku Teks
Hicks, Herbert G., author
McGraw-Hill, 1981
Buku Teks
Spinner, M. Pete, author
Prentice-Hall, 1992
Buku Teks