Shaw, Valerie, author
Longman, Green, 1994
Buku Teks
Delaney, David, author
Blackwell Publishing, 2005
Buku Teks
Tim, Cresswell, author
Wiley , 2015
Buku Teks
Archibald, John M., author
Oxford University Press, 2018
Buku Teks
Boynton, Robert W., author
Boynton/Cook Publishers, 1992
Buku Teks