Hunt, Leon
Routledge , 1998
Buku Teks
edited by Peter Childs, Mike Storry
Routledge, 1999
Buku Referensi
edited by Kwesi Owusu
Routledge , 2000
Buku Teks
Smith, Leslie, author
Macmillan, 1989
Buku Teks
Vandersteen, Willy, author
Standaard, 2012
Buku Teks