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
Robert DeMaria, Robert D. Brown, editor
Blackwell Publishing, 2007
Buku Teks