Turner, Jonathan H.
Goodyear, 1976
Buku Teks
Baltimore : The Linguistic Society of America
Majalah, Jurnal, Buletin
Otto, Mary
The New Press, 2017
Buku Teks
Carroll, John B.
Harvad University Press, 1953
Buku Referensi
Carrol, John
Harvard University Press , 1953
Buku Teks SO