Chambers, J.K., author
Wiley-Blackwell, 2009
Buku Teks
Fathur Rokhman, author
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 1996
UI - Tesis (Membership)
edited by Howard Giles and W. Peter Robinson
John Wiley & Sons, 1990
Buku Referensi
Trudgill, Peter, author
Penguin, 1995
Buku Teks
Singapore University Press, 1980
Buku Teks