Cleveland, Donald B.
Libraries Unlimited, 2001
Buku Referensi
Lancaster, F. Wilfrid
University of Illinois, 1998
Buku Teks
Lancaster, F. Wilfrid
Facet Publishing, 2003
Buku Teks
Rowley, Jennifer
Clive Bingley, 1988
Buku Teks
Stephens, J.
British Library Board, 1983
Buku Referensi