Carmichael, D.G., author
Ellis Horwood, 1981
Buku Teks
Hargreaves, Martin
Longman, 1996
Buku Teks
Martin lambert, Michael Leonard, Andrew Metcalfe
Taylor and Francis, 2009
Buku Teks
Franks, Roger G.E., author
John Wiley & Sons, 1972
Buku Teks
Mosley, W.H. (William Henry), author
Macmillan, 1984
Buku Teks