18 January 2016 The Future of IPv4
25 September 2015 BBC News: Old net addresses run out in US and Canada
24 February 2011 The 6 biggest misconceptions about IPV6
17 August 2012 30 Percent of IPV4 Space is Still Unused
13 November 2008 Article by Dyn research: For Sale: Clean, Lightly Used IP Address?