Jaakko Hollmén, editor
Springer-Verlag, 2012
eBooks
O`Dell, Jerry W., author
TAB Books, 1984
Buku Teks
Ryan, Barbara, author
Brooks/Cole Cengage Learning, 2013
Buku Teks
Digby, Pete
Clarendon Press , 1989
Buku Teks
Snell, E. J., author
Chapman and Hall, 1991
Buku Referensi