Flemming, Laraine E.
Hougtton-Mifflin, 1996
Buku Teks
Presley, John W.
Holt, Rinehart and Winston, 1980
Buku Teks
Spaventa, Lou J.
McGraw-Hill, 2001
Buku Teks
Kelly, Curtis
Cambridge university press, 2008
Buku Teks
Kelly, Curtis
Cambridge university press, 2010
Buku Teks