Wiarda, Howard J., author
Thomson Wadsworth, 2000
Buku Teks
Castaneda, Liliana Blanco, author
Wiley , 2012
Buku Teks
Venables, John A., author
Cambridge University Press, 2000
Buku Teks
Knapp, Brian, author
Longman House, 1992
Buku Teks
Walter, Eugene Victor, author
Chapel Hill, 1988
Buku Teks