Lehmann, John
AB LJUS, 1946
Buku Teks
edited by Susan Brindley
Routledge, 1993
Buku Teks SO
Hyland, Ken
Longman, 2002
Buku Teks
Peters, Herman Jacob, 1917-
Macmillan, 1963
Buku Teks
Pike, Kenneth L. (Kenneth Lee), 1912-2000
Summer institute of linguistics, 1946
Buku Teks SO