Dancygier, Barbara, author
Cambridge University Press, 2006
Buku Teks
Pack, Alice C.
Newbury House Pub., 1980
Buku Teks
Brandon, Lee, 1965-1993, author
Wadsworth and Cengage Learning, 2012
Buku Teks
Langan, John, 1942-, author
McGraw-Hill, 1994
Buku Teks
Diessel, Holger, author
Cambridge University Press, 2006
Buku Teks