1. [BSI09] Sichere Nutzung von WLAN (ISi-WLAN), BSI-Leitlinie zur Internet-Sicherheit (ISi-L), 2009.
2. [DEN] DENIC. www.denic.de .
3. [IAN] IANA IPv4 Address Space Registry. http://www.iana.org/assignments/ipv4-addressspace/ipv4-address-space.xhtml .
4. [Int] International Network Information Center (InterNIC). www.internic.net .
5. [ISC] ISC Domain Survey. http://www.isc.org/services/survey/ .