Artikel Jurnal
edited by Sohn Ho-min
University of Hawaii, 2006
Buku Teks
Schiffman, Harold F., author
Routledge, 1996
Buku Teks
edited by Alessandro Duranti
Blaxkwell , 2004
Buku Teks
Lambert, Wallace E., author
Stanford University press, 1972
Buku Teks