Japan : Institution for Phonetic Sciences Kyoto University
Majalah, Jurnal, Buletin
Troubetzkoy, N.S.
Gottingen Van der Hoek & Reprecht 1958
Buku Teks
Eringa, Pier
Leiden E.J. Brill 1948
Buku Teks
Troubetzkoy, N.S.
Gottingen Van der Hoek & Reprecht 1958
Buku Teks
The Center for the Study of Islam and Society, {s.a.}
Majalah, Jurnal, Buletin