Gunstream, Stanley E., author
McGraw-Hill, 2006
Buku Teks
Cunningham, Daniel John, author
Oxford University Press, 1957
Buku Teks
Patton, Kevin T., author
Elsevier Mosby, 2013
Buku Teks
Jackson, Sheila M.
The English Language Book, 1979
Buku Teks
Tortora, Gerard J., author
Purdue University, 1998
Buku Teks