Whitehead, Randall, author
Rockport, 1998
Buku Teks
Whitehead, Randal, author
Rockport Publishers, 1999
Buku Referensi
Sudjic, Deyan, author
Mitchell Beazley, 1986
Buku Referensi
Johnson, Glen M., author
McGraw-Hill, 1999
Buku Teks
Johnson, Glenn M., author
McGraw-Hill, 1999
Buku Referensi