Wilhide, Elizabeth
Conran Octopus, 1998
Buku Referensi
Whately, Alice
Pageone, 2002
Buku Referensi
Beazley, Mitchell
Reed Consumer Books, 1990
Buku Referensi
Cuito, Aurora
Loft Publications S.L and HBI, 2002
Buku Teks SO
Leibrock, Cynthia A.
John Wiley & Sons, 2000
Buku Referensi