Fogel, Efi, author
Springer, 2012
eBooks
Drago, Carl, author
Blackwell Publishing, 2007
Buku Referensi
Ziegler, Kathleen, author
Rockport Publishers, 1994
Buku Referensi
Drago, Carl, author
Blackwell, 2014
Buku Teks
Jackson, Paul, author
Chancellor, 1994
Buku Referensi