Beard, Adrian, author
Routledge, 2004
Buku Teks
Herdan, Gustav
P. Noordhoff, 1956
Buku Teks
Bloomfield, Leonard, author
Holt, Rinehart and Winston, 1961
Buku Teks
Klein, Wolfgang
Routledge , 1997
Buku Teks
edited by Joseph H. Greenberg
MIT Press, 1966
Buku Teks