Paul Cobley
Routledge , 2001
Buku Teks
Ivic, Milka
Mounton, 1970
Buku Teks
Philipp Strazny, editor
Fitzroy Dearborn, 2005
Buku Referensi
edited by Kirsten Malmkjær
Routledge, 2004
Buku Referensi
Crystal, David, 1941-, author
Westview Press, 1980
Buku Referensi