Laski, Harold J., author
Penguin Books, 1937
Buku Teks
Riley, Jonathan
Routledge, 1998
Buku Teks
Nancy Kranich, editor
[American Library association, ], 2001
eBooks
Hart, H.L.A., author
Standford University Press, 1969
Buku Teks
Shoen, Harriet H.
The L. W. Singer Company, 1955
Buku Teks