Professional .NET Framework 2.0 (Programmer to Programmer)

Mastering Regular Expressions; Jeffrey Friedl; ISBN 0-596-00289-0. O'Reilly, 2002.

Beginning Regular Expressions; Andrew Watt; ISBN 0-764-57489-2. Wrox, 2005.

The Unicode Standard 4.0; The Unicode Consortium; ISBN 0-321-118578-1. Addison-Wesley, 2003; www.unicode.org/versions/Unicode4.0.0.