Norman, Sandy
Facet Publishing, 2004
Buku Teks
Thorn, Eric A.
Jay Books, 1989
Buku Referensi
Strong, William S.
MIT Press, 1981
Buku Teks
Akester, Patricia
Sweet & Maxwell, 2008
Buku Referensi
Akester, Patricia
Sweet & Maxwel, [Date of publication not identified]
Buku Teks