Ellis, Robert
Harcourt Brace Javanovich, 1978
Buku Teks SO
London Collier-Macmillan 1965,
Buku Teks
Flesch, Rudolf
Harper & Brothers, 1958
Buku Teks SO
Suenobu, Mineo
Kobe University of Commerce, 1999
Buku Teks SO
Fred Genesee, Kathryn Lindholm-Leary, William M. Saunders, Donna Christian
Cambridge University Press, 2008
Buku Teks SO