Schlesinger, Arthur Meier
The politics of hope
Houghton Mifflin, 1962
 Buku Teks SO
Pelton, Gordon E.
Voice processing
McGraw-Hill, 1992
 Buku Teks SO
Klaiman, M.H.
Grammatical voice
Cambridge University Press , 1991
 Buku Teks SO
Klevans, Richard L.
Voice recognition
Artech House, 1997
 Buku Teks SO
Klevans, Richard L.
Voice recognition
Artech House, 1997
 Buku Teks