Schiffman, Harold F.
Routledge, 1996
Buku Teks
Sandler, Wendy
Cambridge University Press, 2006
Buku Teks
edited by Ralph Ludwig, Peter Mühlhäusler and Steve Pagel
Cambridge University Press, 2019
Buku Teks
Ledgrad, Henry
Science Research Association, 1981
Buku Teks
Moulton, William G.
Modern Language Association of America, 1966
Buku Teks SO