Groarke, Leo, author
Oxford University Press , 1997
Buku Teks
Numrich, Carol
Longman, 1994
Buku Teks
Jackson, Sherri L., author
Thomson Wadsworth, 2006
Buku Teks
Jackson, Sherri L., author
Thomson Wadsworth, 2003
Buku Teks
Jackson, Sherri L., author
Wadsworth and Cengage Learning, 2012
Buku Teks