Dunn, Dana S., author
Longman, 2011
Buku Teks
Itule, Bruce D., author
McGraw-Hill, 1994
Buku Teks
Pechenik, Jan A., author
Pearson Longman, 2007
Buku Teks
Pechenik, Jan A., author
Longman , 2001
Buku Teks
O`Shea, Robert P. (Robert Paul), 1953-, author
Harcourt Brace & Company, 1996
Buku Teks