Puchta, Herbert
Cambridge University Press, 2010
Buku Teks
Dignen, Bob, author
York Associates, 1999
Buku Teks
Dignen, Bob, author
York Associates, 1999
Buku Teks
Jaderstrom, Susan, author
McGraw-Hill Glencoe, 2003
Buku Teks
Jones, Leo
Cambridge University Press, 1989
Buku Teks