Fries, Charles Carpenter
University of Michigan Press, 1951
Buku Teks SO
edited by Michael McCarthy
Cambridge University Press, 2016
Buku Teks SO
Cook, Vivian
Edward Arnold, 2001
Buku Teks SO
Brown, Douglas
Pearson Longman, 2007
Buku Teks SO
Routledge, 2004
Buku Teks