Ahrens, C. Donald
Brooks/Cole, Cengage Learning, , 2011
Buku Teks
Barry, Roger G.
Routledge, 1998
Buku Teks
Aguado, Edward
Prentice-Hall, 2001
Buku Teks
Mitchell-Christie, Frank
William Luscombe , 1977
Buku Teks
Ahrens, C. Donald
Thomson, Brooks/Cole, 2007
Buku Teks