Potts, Vanessa
Monet
Parragon, 2001
Buku Referensi
Potts, Vanessa
Monet/Vanessa Potts
Bath, Inggris Paragon 2001,
Buku Referensi
Ebert, Ronald J.
Business essential
Prentice-Hall, 1998
Buku Teks
Broughton, Vanda
Essential classification
Facet, 2004
Buku Teks
Bowman, J.H.
Essential dewey
Facet, 2005
Buku Teks