Erber, Joan T., author
Wiley-Blackwell, 2013
Buku Teks
Alan Walker, Liam Foster, editors
Elgar Research Colection, 2014
Buku Teks
Novak, Mark, author
Pearson, 2014
Buku Teks
Novak, Mark, author
Pearson, 2014
Buku Teks
Schultz, Richard, author
Prentice-Hall, 1999
Buku Teks