Pechenik, Jan A.
Pearson Longman, 2007
Buku Teks
Dunn, Dana S.
Longman, 2011
Buku Teks
Clymo, R. S.
Cambridge University Press, 2014.
Buku Teks
Barnet, Sylvan
Batsford Academic and Educational, 1985
Buku Teks
Barnet, Sylvan
Little, Brown, 1979
Buku Teks