Cantrall, William R.
Mouton, 1974
Buku Teks
Berman, Harold J., author
The Fondation Press , 1966
Buku Teks
Giorgi, Alessandra
Cambridge University Press , 1991
Buku Teks
Blake, Frank R.
[publisher not identified], 1912
Buku Klasik
Rock, William R.
Twayne Publishers, 1969
Buku Teks