edited by Diane Brentari
Cambridge University Press, 2010
Buku Teks
Llamzon, Teodore A., author
Martinus Nijhoff, 1969
Buku Teks
editor Derek Bingham
John Catt Educational, 1994
Buku Referensi
Campbell, George L., author
Routledge, 1998
Buku Teks
Stokoe, William C., author
Mouton, 1972
Buku Teks