Grassian, Daniel
McFarland and Company, 1992
Buku Teks
Hilfer, Tony, author
Longman, 1992
Buku Teks
Lee, Brian, author
Longman , 1993
Buku Teks
Hanna, Archibald, 1916-2010, author
Garland Publishing, 1985
Buku Referensi
Horner, Avril, author
Harvester Wheatshea, 1990
Buku Teks