Brown, Wilfred
Heinemann, 1971
Buku Teks
Champion, Dean J., author
McGraw-Hill, 1975
Buku Teks
Brech, E.F.L., author
Longmans, Green & Co. , 1957
Buku Teks
Brech, E.F.L., author
Longman , 1970
Buku Teks
Drucker, Peter F. (Peter Ferdinand), 1909-2005, author
Harper & Brothers, 1950
Buku Teks