Artikel Jurnal
Gorman, G.E., author
Hans Zell Publishers, 1992
Buku Referensi
Cleveland, Donald B., author
Libraries Unlimited, 2013
Buku Teks
Cleveland, Donald B., author
Libraries Unlimited , 2001
Buku Teks
Lancaster, F. Wilfrid, author
Facet Publishing, 2003
Buku Teks