Hoenigswald, Henry R.M.
University of Chicago Press , 1960
Buku Teks SO
edited by Raymond Hickey
Cambridge University Press, 2004
eBooks
by Laurel J. Brinton and Elizabeth Closs Traugott
Cambridge University Press, 2005
eBooks
edited by Stefano Bertolo
Cambridge University Press, 2001
eBooks
Trudgill, Peter
Cambridge University Press, 2010
eBooks