Cotterell, John
Lorenz Books, 2000
Buku Referensi
Harris, Stephen L, 1937-2004
McGraw-Hill, 2012
Buku Teks
Cooper, Hazel Dixon
Torrent Books, 2004
Buku Teks
Sykes, Egerton
London, J.M. Dent and Sons
Buku Referensi
edited by Robert DeMaria and Robert D. Brown
Blackwell, 2007
Buku Teks