edited by Beth A. Simmons and Richard H. Steinberg
Cambridge University Press, 2006
Buku Teks
Hill, Norman, author
Harper & Brothers, 1952
Buku Teks
Appleyard, Dennis R., author
McGraw-Hill, 2014
Buku Teks
by George Zis ... [et al.]
Longman, 1988
Buku Teks
King, Philip, author
McGraww-Hill, 1990
Buku Teks