Bradbury, Phil, author
Colo Libraries Unlimited , 1989
Buku Teks
Kalfatovic, Martin R., author
[American Library association, American Library association], 2002
eBooks
Eberhart, George M., author
[American Library association, American Library association], 2006
eBooks
edited by Sandy Dolnick
American Library Association , 1990
Buku Teks
Balloffet, Nelly, author
[American Library association, ], 2005
eBooks