John Wiley & Sons Inc, 2017
Buku Teks
Cotterell, John, author
Lorenz Books, 2000
Buku Referensi
Harris, Stephen L, 1937-2004, author
McGraw-Hill, 2012
Buku Teks
Cooper, Hazel Dixon, author
Torrent Books, 2004
Buku Teks
Sykes, Egerton, author
London, J.M. Dent and Sons
Buku Referensi